diff --git a/CodePush.m b/CodePush.m
index 89a41d4..2cc25fa 100644
--- a/CodePush.m
+++ b/CodePush.m
@@ -366,32 +366,34 @@ RCT_EXPORT_METHOD(downloadUpdate:(NSDictionary*)updatePackage
                         resolver:(RCTPromiseResolveBlock)resolve
                         rejecter:(RCTPromiseRejectBlock)reject)
 {
-    [CodePushPackage downloadPackage:updatePackage
-        // The download is progressing forward
-        progressCallback:^(long long expectedContentLength, long long receivedContentLength) {
-            // Notify the script-side about the progress
-            [self.bridge.eventDispatcher
-                sendDeviceEventWithName:@"CodePushDownloadProgress"
-                body:@{
-                        @"totalBytes":[NSNumber numberWithLongLong:expectedContentLength],
-                        @"receivedBytes":[NSNumber numberWithLongLong:receivedContentLength]
-                      }];
-        }
-        // The download completed
-        doneCallback:^{
-            NSError *err;
-            NSDictionary *newPackage = [CodePushPackage getPackage:updatePackage[PackageHashKey] error:&err];
-            
-            if (err) {
-                return reject(err);
+    dispatch_async(dispatch_get_main_queue(), ^{
+        [CodePushPackage downloadPackage:updatePackage
+            // The download is progressing forward
+            progressCallback:^(long long expectedContentLength, long long receivedContentLength) {
+                // Notify the script-side about the progress
+                [self.bridge.eventDispatcher
+                    sendDeviceEventWithName:@"CodePushDownloadProgress"
+                    body:@{
+                            @"totalBytes":[NSNumber numberWithLongLong:expectedContentLength],
+                            @"receivedBytes":[NSNumber numberWithLongLong:receivedContentLength]
+                          }];
             }
-            
-            resolve(newPackage);
-        }
-        // The download failed
-        failCallback:^(NSError *err) {
-            reject(err);
-        }];
+            // The download completed
+            doneCallback:^{
+                NSError *err;
+                NSDictionary *newPackage = [CodePushPackage getPackage:updatePackage[PackageHashKey] error:&err];
+                    
+                if (err) {
+                    return reject(err);
+                }
+                    
+                resolve(newPackage);
+            }
+            // The download failed
+            failCallback:^(NSError *err) {
+                reject(err);
+            }];
+    });
 }
 
 /*
diff --git a/android/app/src/main/java/com/microsoft/codepush/react/CodePush.java b/android/app/src/main/java/com/microsoft/codepush/react/CodePush.java
index 937806f..a247724 100644
--- a/android/app/src/main/java/com/microsoft/codepush/react/CodePush.java
+++ b/android/app/src/main/java/com/microsoft/codepush/react/CodePush.java
@@ -425,41 +425,50 @@ public class CodePush {
         }
 
         @ReactMethod
-        public void getNewStatusReport(Promise promise) {
-            if (needToReportRollback) {
-                needToReportRollback = false;
-                JSONArray failedUpdates = getFailedUpdates();
-                if (failedUpdates != null && failedUpdates.length() > 0) {
-                    try {
-                        JSONObject lastFailedPackageJSON = failedUpdates.getJSONObject(failedUpdates.length() - 1);
-                        WritableMap lastFailedPackage = CodePushUtils.convertJsonObjectToWriteable(lastFailedPackageJSON);
-                        WritableMap failedStatusReport = codePushTelemetryManager.getRollbackReport(lastFailedPackage);
-                        if (failedStatusReport != null) {
-                            promise.resolve(failedStatusReport);
-                            return;
-                        }
-                    } catch (JSONException e) {
-                        throw new CodePushUnknownException("Unable to read failed updates information stored in SharedPreferences.", e);
-                    }
-                }
-            } else if (didUpdate) {
-                WritableMap currentPackage = codePushPackage.getCurrentPackage();
-                if (currentPackage != null) {
-                    WritableMap newPackageStatusReport = codePushTelemetryManager.getUpdateReport(currentPackage);
-                    if (newPackageStatusReport != null) {
-                        promise.resolve(newPackageStatusReport);
-                        return;
-                    }
-                }
-            } else if (isRunningBinaryVersion) {
-                WritableMap newAppVersionStatusReport = codePushTelemetryManager.getBinaryUpdateReport(appVersion);
-                if (newAppVersionStatusReport != null) {
-                    promise.resolve(newAppVersionStatusReport);
-                    return;
-                }
-            }
+        public void getNewStatusReport(final Promise promise) {
 
-            promise.resolve("");
+            AsyncTask asyncTask = new AsyncTask() {
+                @Override
+                protected Void doInBackground(Object... params) {
+                    if (needToReportRollback) {
+                        needToReportRollback = false;
+                        JSONArray failedUpdates = getFailedUpdates();
+                        if (failedUpdates != null && failedUpdates.length() > 0) {
+                            try {
+                                JSONObject lastFailedPackageJSON = failedUpdates.getJSONObject(failedUpdates.length() - 1);
+                                WritableMap lastFailedPackage = CodePushUtils.convertJsonObjectToWriteable(lastFailedPackageJSON);
+                                WritableMap failedStatusReport = codePushTelemetryManager.getRollbackReport(lastFailedPackage);
+                                if (failedStatusReport != null) {
+                                    promise.resolve(failedStatusReport);
+                                    return null;
+                                }
+                            } catch (JSONException e) {
+                                throw new CodePushUnknownException("Unable to read failed updates information stored in SharedPreferences.", e);
+                            }
+                        }
+                    } else if (didUpdate) {
+                        WritableMap currentPackage = codePushPackage.getCurrentPackage();
+                        if (currentPackage != null) {
+                            WritableMap newPackageStatusReport = codePushTelemetryManager.getUpdateReport(currentPackage);
+                            if (newPackageStatusReport != null) {
+                                promise.resolve(newPackageStatusReport);
+                                return null;
+                            }
+                        }
+                    } else if (isRunningBinaryVersion) {
+                        WritableMap newAppVersionStatusReport = codePushTelemetryManager.getBinaryUpdateReport(appVersion);
+                        if (newAppVersionStatusReport != null) {
+                            promise.resolve(newAppVersionStatusReport);
+                            return null;
+                        }
+                    }
+
+                    promise.resolve("");
+                    return null;
+                }
+            };
+
+            asyncTask.execute();
         }
 
         @ReactMethod
diff --git a/android/app/src/main/java/com/microsoft/codepush/react/CodePushInvalidUpdateException.java b/android/app/src/main/java/com/microsoft/codepush/react/CodePushInvalidUpdateException.java
new file mode 100644
index 0000000..b678959
--- /dev/null
+++ b/android/app/src/main/java/com/microsoft/codepush/react/CodePushInvalidUpdateException.java
@@ -0,0 +1,7 @@
+package com.microsoft.codepush.react;
+
+public class CodePushInvalidUpdateException extends RuntimeException {
+    public CodePushInvalidUpdateException() {
+        super("Update is invalid - no files with extension .bundle, .js or .jsbundle were found in the update package.");
+    }
+}
diff --git a/android/app/src/main/java/com/microsoft/codepush/react/CodePushPackage.java b/android/app/src/main/java/com/microsoft/codepush/react/CodePushPackage.java
index d91364a..80645cb 100644
--- a/android/app/src/main/java/com/microsoft/codepush/react/CodePushPackage.java
+++ b/android/app/src/main/java/com/microsoft/codepush/react/CodePushPackage.java
@@ -2,10 +2,14 @@ package com.microsoft.codepush.react;
 
 import android.content.Context;
 
+import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.bridge.ReadableMap;
 import com.facebook.react.bridge.WritableMap;
 import com.facebook.react.bridge.WritableNativeMap;
 
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
 import java.io.File;
@@ -14,18 +18,23 @@ import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.nio.ByteBuffer;
 
 public class CodePushPackage {
 
     public final String CODE_PUSH_FOLDER_PREFIX = "CodePush";
-    public final String STATUS_FILE = "codepush.json";
-    public final String UPDATE_BUNDLE_FILE_NAME = "app.jsbundle";
     public final String CURRENT_PACKAGE_KEY = "currentPackage";
-    public final String PREVIOUS_PACKAGE_KEY = "previousPackage";
+    public final String DIFF_MANIFEST_FILE_NAME = "hotcodepush.json";
+    public final int DOWNLOAD_BUFFER_SIZE = 1024 * 256;
+    public final String DOWNLOAD_FILE_NAME = "download.zip";
+    public final String DOWNLOAD_URL_KEY = "downloadUrl";
     public final String PACKAGE_FILE_NAME = "app.json";
     public final String PACKAGE_HASH_KEY = "packageHash";
-    public final String DOWNLOAD_URL_KEY = "downloadUrl";
-    public final int DOWNLOAD_BUFFER_SIZE = 1024 * 256;
+    public final String PREVIOUS_PACKAGE_KEY = "previousPackage";
+    public final String RELATIVE_BUNDLE_PATH_KEY = "bundlePath";
+    public final String STATUS_FILE = "codepush.json";
+    public final String UNZIPPED_FOLDER_NAME = "unzipped";
+    public final String UPDATE_BUNDLE_FILE_NAME = "app.jsbundle";
 
     private String documentsDirectory;
 
@@ -33,6 +42,14 @@ public class CodePushPackage {
         this.documentsDirectory = documentsDirectory;
     }
 
+    public String getDownloadFilePath() {
+        return CodePushUtils.appendPathComponent(getCodePushPath(), DOWNLOAD_FILE_NAME);
+    }
+
+    public String getUnzippedFolderPath() {
+        return CodePushUtils.appendPathComponent(getCodePushPath(), UNZIPPED_FOLDER_NAME);
+    }
+
     public String getDocumentsDirectory() {
         return documentsDirectory;
     }
@@ -52,7 +69,7 @@ public class CodePushPackage {
 
     public WritableMap getCurrentPackageInfo() {
         String statusFilePath = getStatusFilePath();
-        if (!CodePushUtils.fileAtPathExists(statusFilePath)) {
+        if (!FileUtils.fileAtPathExists(statusFilePath)) {
             return new WritableNativeMap();
         }
 
@@ -87,7 +104,13 @@ public class CodePushPackage {
             return null;
         }
 
-        return CodePushUtils.appendPathComponent(packageFolder, UPDATE_BUNDLE_FILE_NAME);
+        WritableMap currentPackage = getCurrentPackage();
+        String relativeBundlePath = CodePushUtils.tryGetString(currentPackage, RELATIVE_BUNDLE_PATH_KEY);
+        if (relativeBundlePath == null) {
+            return CodePushUtils.appendPathComponent(packageFolder, UPDATE_BUNDLE_FILE_NAME);
+        } else {
+            return CodePushUtils.appendPathComponent(packageFolder, relativeBundlePath);
+        }
     }
 
     public String getPackageFolderPath(String packageHash) {
@@ -132,7 +155,7 @@ public class CodePushPackage {
     public void downloadPackage(Context applicationContext, ReadableMap updatePackage,
                                 DownloadProgressCallback progressCallback) throws IOException {
 
-        String packageFolderPath = getPackageFolderPath(CodePushUtils.tryGetString(updatePackage, PACKAGE_HASH_KEY));
+        String newPackageFolderPath = getPackageFolderPath(CodePushUtils.tryGetString(updatePackage, PACKAGE_HASH_KEY));
         String downloadUrlString = CodePushUtils.tryGetString(updatePackage, DOWNLOAD_URL_KEY);
 
         URL downloadUrl = null;
@@ -140,7 +163,10 @@ public class CodePushPackage {
         BufferedInputStream bin = null;
         FileOutputStream fos = null;
         BufferedOutputStream bout = null;
+        File downloadFile = null;
+        boolean isZip = false;
 
+        // Download the file while checking if it is a zip and notifying client of progress.
         try {
             downloadUrl = new URL(downloadUrlString);
             connection = (HttpURLConnection) (downloadUrl.openConnection());
@@ -149,23 +175,34 @@ public class CodePushPackage {
             long receivedBytes = 0;
 
             bin = new BufferedInputStream(connection.getInputStream());
-            File downloadFolder = new File(packageFolderPath);
+            File downloadFolder = new File(getCodePushPath());
             downloadFolder.mkdirs();
-            File downloadFile = new File(downloadFolder, UPDATE_BUNDLE_FILE_NAME);
+            downloadFile = new File(downloadFolder, DOWNLOAD_FILE_NAME);
             fos = new FileOutputStream(downloadFile);
             bout = new BufferedOutputStream(fos, DOWNLOAD_BUFFER_SIZE);
             byte[] data = new byte[DOWNLOAD_BUFFER_SIZE];
+            byte[] header = new byte[4];
+
             int numBytesRead = 0;
             while ((numBytesRead = bin.read(data, 0, DOWNLOAD_BUFFER_SIZE)) >= 0) {
+                if (receivedBytes < 4) {
+                    for (int i = 0; i < numBytesRead; i++) {
+                        int headerOffset = (int)(receivedBytes) + i;
+                        if (headerOffset >= 4) {
+                            break;
+                        }
+
+                        header[headerOffset] = data[i];
+                    }
+                }
+
                 receivedBytes += numBytesRead;
                 bout.write(data, 0, numBytesRead);
                 progressCallback.call(new DownloadProgress(totalBytes, receivedBytes));
             }
 
             assert totalBytes == receivedBytes;
-
-            String bundlePath = CodePushUtils.appendPathComponent(packageFolderPath, PACKAGE_FILE_NAME);
-            CodePushUtils.writeReadableMapToFile(updatePackage, bundlePath);
+            isZip = ByteBuffer.wrap(header).getInt() == 0x504b0304;
         } catch (MalformedURLException e) {
             throw new CodePushMalformedDataException(downloadUrlString, e);
         } finally {
@@ -178,6 +215,51 @@ public class CodePushPackage {
                 throw new CodePushUnknownException("Error closing IO resources.", e);
             }
         }
+
+        if (isZip) {
+            // Unzip the downloaded file and then delete the zip
+            String unzippedFolderPath = getUnzippedFolderPath();
+            FileUtils.unzipFile(downloadFile, unzippedFolderPath);
+            FileUtils.deleteFileSilently(downloadFile);
+
+            // Merge contents with current update based on the manifest
+            String diffManifestFilePath = CodePushUtils.appendPathComponent(unzippedFolderPath,
+                    DIFF_MANIFEST_FILE_NAME);
+            if (FileUtils.fileAtPathExists(diffManifestFilePath)) {
+                String currentPackageFolderPath = getCurrentPackageFolderPath();
+                CodePushUpdateUtils.copyNecessaryFilesFromCurrentPackage(diffManifestFilePath, currentPackageFolderPath, newPackageFolderPath);
+            }
+
+            FileUtils.copyDirectoryContents(unzippedFolderPath, newPackageFolderPath);
+            FileUtils.deleteFileAtPathSilently(unzippedFolderPath);
+
+            // For zip updates, we need to find the relative path to the jsBundle and save it in the
+            // metadata so that we can find and run it easily the next time.
+            String relativeBundlePath = CodePushUpdateUtils.findJSBundleInUpdateContents(newPackageFolderPath);
+
+            if (relativeBundlePath == null) {
+                throw new CodePushInvalidUpdateException();
+            } else {
+                JSONObject updatePackageJSON = CodePushUtils.convertReadableToJsonObject(updatePackage);
+                try {
+                    updatePackageJSON.put(RELATIVE_BUNDLE_PATH_KEY, relativeBundlePath);
+                } catch (JSONException e) {
+                    throw new CodePushUnknownException("Unable to set key " +
+                            RELATIVE_BUNDLE_PATH_KEY + " to value " + relativeBundlePath +
+                            " in update package.", e);
+                }
+                
+                updatePackage = CodePushUtils.convertJsonObjectToWriteable(updatePackageJSON);
+            }
+        } else {
+            // File is a jsBundle, move it to a folder with the packageHash as its name
+            File updateBundleFile = new File(newPackageFolderPath, UPDATE_BUNDLE_FILE_NAME);
+            downloadFile.renameTo(updateBundleFile);
+        }
+
+        // Save metadata to the folder.
+        String bundlePath = CodePushUtils.appendPathComponent(newPackageFolderPath, PACKAGE_FILE_NAME);
+        CodePushUtils.writeReadableMapToFile(updatePackage, bundlePath);
     }
 
     public void installPackage(ReadableMap updatePackage) throws IOException {
@@ -185,7 +267,7 @@ public class CodePushPackage {
         WritableMap info = getCurrentPackageInfo();
         String previousPackageHash = getPreviousPackageHash();
         if (previousPackageHash != null && !previousPackageHash.equals(packageHash)) {
-            CodePushUtils.deleteDirectoryAtPath(getPackageFolderPath(previousPackageHash));
+            FileUtils.deleteDirectoryAtPath(getPackageFolderPath(previousPackageHash));
         }
 
         info.putString(PREVIOUS_PACKAGE_KEY, CodePushUtils.tryGetString(info, CURRENT_PACKAGE_KEY));
@@ -196,7 +278,7 @@ public class CodePushPackage {
     public void rollbackPackage() {
         WritableMap info = getCurrentPackageInfo();
         String currentPackageFolderPath = getCurrentPackageFolderPath();
-        CodePushUtils.deleteDirectoryAtPath(currentPackageFolderPath);
+        FileUtils.deleteDirectoryAtPath(currentPackageFolderPath);
         info.putString(CURRENT_PACKAGE_KEY, CodePushUtils.tryGetString(info, PREVIOUS_PACKAGE_KEY));
         info.putNull(PREVIOUS_PACKAGE_KEY);
         updateCurrentPackageInfo(info);
@@ -238,6 +320,6 @@ public class CodePushPackage {
     public void clearUpdates() {
         File statusFile = new File(getStatusFilePath());
         statusFile.delete();
-        CodePushUtils.deleteDirectoryAtPath(getCodePushPath());
+        FileUtils.deleteDirectoryAtPath(getCodePushPath());
     }
 }
diff --git a/android/app/src/main/java/com/microsoft/codepush/react/CodePushUpdateUtils.java b/android/app/src/main/java/com/microsoft/codepush/react/CodePushUpdateUtils.java
new file mode 100644
index 0000000..a8cd21c
--- /dev/null
+++ b/android/app/src/main/java/com/microsoft/codepush/react/CodePushUpdateUtils.java
@@ -0,0 +1,46 @@
+package com.microsoft.codepush.react;
+
+import com.facebook.react.bridge.ReadableArray;
+import com.facebook.react.bridge.WritableMap;
+
+import java.io.File;
+import java.io.IOException;
+
+public class CodePushUpdateUtils {
+
+    public static void copyNecessaryFilesFromCurrentPackage(String diffManifestFilePath, String currentPackageFolderPath, String newPackageFolderPath) throws IOException{
+        FileUtils.copyDirectoryContents(currentPackageFolderPath, newPackageFolderPath);
+        WritableMap diffManifest = CodePushUtils.getWritableMapFromFile(diffManifestFilePath);
+        ReadableArray deletedFiles = diffManifest.getArray("deletedFiles");
+        for (int i = 0; i < deletedFiles.size(); i++) {
+            String fileNameToDelete = deletedFiles.getString(i);
+            File fileToDelete = new File(newPackageFolderPath, fileNameToDelete);
+            FileUtils.deleteFileSilently(fileToDelete);
+        }
+    }
+
+    public static String findJSBundleInUpdateContents(String folderPath) {
+        File folder = new File(folderPath);
+        File[] folderFiles = folder.listFiles();
+        for (File file : folderFiles) {
+            String fullFilePath = CodePushUtils.appendPathComponent(folderPath, file.getName());
+            if (file.isDirectory()) {
+                String mainBundlePathInSubFolder = findJSBundleInUpdateContents(fullFilePath);
+                if (mainBundlePathInSubFolder != null) {
+                    return CodePushUtils.appendPathComponent(file.getName(), mainBundlePathInSubFolder);
+                }
+            } else {
+                String fileName = file.getName();
+                int dotIndex = fileName.lastIndexOf(".");
+                if (dotIndex >= 0) {
+                    String fileExtension = fileName.substring(dotIndex + 1);
+                    if (fileExtension.equals("bundle") || fileExtension.equals("js") || fileExtension.equals("jsbundle")) {
+                        return fileName;
+                    }
+                }
+            }
+        }
+
+        return null;
+    }
+}
diff --git a/android/app/src/main/java/com/microsoft/codepush/react/CodePushUtils.java b/android/app/src/main/java/com/microsoft/codepush/react/CodePushUtils.java
index 295fc37..63d2709 100644
--- a/android/app/src/main/java/com/microsoft/codepush/react/CodePushUtils.java
+++ b/android/app/src/main/java/com/microsoft/codepush/react/CodePushUtils.java
@@ -15,99 +15,57 @@ import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 
+import java.io.BufferedInputStream;
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.PrintWriter;
 import java.util.Iterator;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
 
 public class CodePushUtils {
 
+    public static final String CODE_PUSH_TAG = "CodePush";
     public static final String REACT_NATIVE_LOG_TAG = "ReactNative";
 
     public static String appendPathComponent(String basePath, String appendPathComponent) {
         return new File(basePath, appendPathComponent).getAbsolutePath();
     }
 
-    public static boolean fileAtPathExists(String filePath) {
-        return new File(filePath).exists();
-    }
-
-    public static String readFileToString(String filePath) throws IOException {
-        FileInputStream fin = null;
-        BufferedReader reader = null;
-        try {
-            File fl = new File(filePath);
-            fin = new FileInputStream(fl);
-            reader = new BufferedReader(new InputStreamReader(fin));
-            StringBuilder sb = new StringBuilder();
-            String line = null;
-            while ((line = reader.readLine()) != null) {
-                sb.append(line).append("\n");
+    public static WritableArray convertJsonArrayToWriteable(JSONArray jsonArr) {
+        WritableArray arr = Arguments.createArray();
+        for (int i=0; i<jsonArr.length(); i++) {
+            Object obj = null;
+            try {
+                obj = jsonArr.get(i);
+            } catch (JSONException jsonException) {
+                // Should not happen.
+                throw new CodePushUnknownException(i + " should be within bounds of array " + jsonArr.toString(), jsonException);
             }
 
-            return sb.toString();
-        } finally {
-            if (reader != null) reader.close();
-            if (fin != null) fin.close();
-        }
-    }
-
-    public static void writeStringToFile(String content, String filePath) throws IOException {
-        PrintWriter out = null;
-        try {
-            out = new PrintWriter(filePath);
-            out.print(content);
-        } finally {
-            if (out != null) out.close();
-        }
-    }
-
-    public static void deleteDirectoryAtPath(String directoryPath) {
-        deleteDirectory(new File(directoryPath));
-    }
-
-    public static void deleteDirectory(File directory) {
-        if (directory.exists()) {
-            File[] files = directory.listFiles();
-            if (files != null) {
-                for (int i=0; i<files.length; i++) {
-                    if(files[i].isDirectory()) {
-                        deleteDirectory(files[i]);
-                    }
-                    else {
-                        files[i].delete();
-                    }
-                }
-            }
-        }
-        directory.delete();
-    }
-
-    public static boolean createFolderAtPath(String filePath) {
-        File file = new File(filePath);
-        return file.mkdir();
-    }
-
-    public static WritableMap getWritableMapFromFile(String filePath) throws IOException {
-
-        String content = CodePushUtils.readFileToString(filePath);
-        JSONObject json = null;
-        try {
-            json = new JSONObject(content);
-            return convertJsonObjectToWriteable(json);
-        } catch (JSONException jsonException) {
-            throw new CodePushMalformedDataException(filePath, jsonException);
+            if (obj instanceof JSONObject)
+                arr.pushMap(convertJsonObjectToWriteable((JSONObject) obj));
+            else if (obj instanceof JSONArray)
+                arr.pushArray(convertJsonArrayToWriteable((JSONArray) obj));
+            else if (obj instanceof String)
+                arr.pushString((String) obj);
+            else if (obj instanceof Double)
+                arr.pushDouble((Double) obj);
+            else if (obj instanceof Integer)
+                arr.pushInt((Integer) obj);
+            else if (obj instanceof Boolean)
+                arr.pushBoolean((Boolean) obj);
+            else if (obj == null)
+                arr.pushNull();
+            else
+                throw new CodePushUnknownException("Unrecognized object: " + obj);
         }
 
-    }
-
-    public static void writeReadableMapToFile(ReadableMap map, String filePath) throws IOException {
-        JSONObject json = CodePushUtils.convertReadableToJsonObject(map);
-        String jsonString = json.toString();
-        CodePushUtils.writeStringToFile(jsonString, filePath);
+        return arr;
     }
 
     public static WritableMap convertJsonObjectToWriteable(JSONObject jsonObj) {
@@ -144,73 +102,9 @@ public class CodePushUtils {
         return map;
     }
 
-    public static WritableArray convertJsonArrayToWriteable(JSONArray jsonArr) {
-        WritableArray arr = Arguments.createArray();
-        for (int i=0; i<jsonArr.length(); i++) {
-            Object obj = null;
-            try {
-                obj = jsonArr.get(i);
-            } catch (JSONException jsonException) {
-                // Should not happen.
-                throw new CodePushUnknownException(i + " should be within bounds of array " + jsonArr.toString(), jsonException);
-            }
-
-            if (obj instanceof JSONObject)
-                arr.pushMap(convertJsonObjectToWriteable((JSONObject) obj));
-            else if (obj instanceof JSONArray)
-                arr.pushArray(convertJsonArrayToWriteable((JSONArray) obj));
-            else if (obj instanceof String)
-                arr.pushString((String) obj);
-            else if (obj instanceof Double)
-                arr.pushDouble((Double) obj);
-            else if (obj instanceof Integer)
-                arr.pushInt((Integer) obj);
-            else if (obj instanceof Boolean)
-                arr.pushBoolean((Boolean) obj);
-            else if (obj == null)
-                arr.pushNull();
-            else
-                throw new CodePushUnknownException("Unrecognized object: " + obj);
-        }
-
-        return arr;
-    }
-
-    public static JSONObject convertReadableToJsonObject(ReadableMap map) {
-        JSONObject jsonObj = new JSONObject();
-        ReadableMapKeySetIterator it = map.keySetIterator();
-        while (it.hasNextKey()) {
-            String key = it.nextKey();
-            ReadableType type = map.getType(key);
-            try {
-                switch (type) {
-                    case Map:
-                        jsonObj.put(key, convertReadableToJsonObject(map.getMap(key)));
-                        break;
-                    case Array:
-                        jsonObj.put(key, convertReadableToJsonArray(map.getArray(key)));
-                        break;
-                    case String:
-                        jsonObj.put(key, map.getString(key));
-                        break;
-                    case Number:
-                        jsonObj.put(key, map.getDouble(key));
-                        break;
-                    case Boolean:
-                        jsonObj.put(key, map.getBoolean(key));
-                        break;
-                    case Null:
-                        jsonObj.put(key, null);
-                        break;
-                    default:
-                        throw new CodePushUnknownException("Unrecognized type: " + type + " of key: " + key);
-                }
-            } catch (JSONException jsonException) {
-                throw new CodePushUnknownException("Error setting key: " + key + " in JSONObject", jsonException);
-            }
-        }
-
-        return jsonObj;
+    public static WritableMap convertReadableMapToWritableMap(ReadableMap map) {
+        JSONObject mapJSON = convertReadableToJsonObject(map);
+        return convertJsonObjectToWriteable(mapJSON);
     }
 
     public static JSONArray convertReadableToJsonArray(ReadableArray arr) {
@@ -252,9 +146,62 @@ public class CodePushUtils {
         return jsonArr;
     }
 
-    public static WritableMap convertReadableMapToWritableMap(ReadableMap map) {
-        JSONObject mapJSON = convertReadableToJsonObject(map);
-        return convertJsonObjectToWriteable(mapJSON);
+    public static JSONObject convertReadableToJsonObject(ReadableMap map) {
+        JSONObject jsonObj = new JSONObject();
+        ReadableMapKeySetIterator it = map.keySetIterator();
+        while (it.hasNextKey()) {
+            String key = it.nextKey();
+            ReadableType type = map.getType(key);
+            try {
+                switch (type) {
+                    case Map:
+                        jsonObj.put(key, convertReadableToJsonObject(map.getMap(key)));
+                        break;
+                    case Array:
+                        jsonObj.put(key, convertReadableToJsonArray(map.getArray(key)));
+                        break;
+                    case String:
+                        jsonObj.put(key, map.getString(key));
+                        break;
+                    case Number:
+                        jsonObj.put(key, map.getDouble(key));
+                        break;
+                    case Boolean:
+                        jsonObj.put(key, map.getBoolean(key));
+                        break;
+                    case Null:
+                        jsonObj.put(key, null);
+                        break;
+                    default:
+                        throw new CodePushUnknownException("Unrecognized type: " + type + " of key: " + key);
+                }
+            } catch (JSONException jsonException) {
+                throw new CodePushUnknownException("Error setting key: " + key + " in JSONObject", jsonException);
+            }
+        }
+
+        return jsonObj;
+    }
+
+    public static WritableMap getWritableMapFromFile(String filePath) throws IOException {
+
+        String content = FileUtils.readFileToString(filePath);
+        JSONObject json = null;
+        try {
+            json = new JSONObject(content);
+            return convertJsonObjectToWriteable(json);
+        } catch (JSONException jsonException) {
+            throw new CodePushMalformedDataException(filePath, jsonException);
+        }
+
+    }
+
+    public static void log(String message) {
+        Log.d(REACT_NATIVE_LOG_TAG, "[CodePush] " + message);
+    }
+
+    public static void logBundleUrl(String path) {
+        log("Loading JS bundle from \"" + path + "\"");
     }
 
     public static String tryGetString(ReadableMap map, String key) {
@@ -265,11 +212,9 @@ public class CodePushUtils {
         }
     }
 
-    public static void log(String message) {
-        Log.d(REACT_NATIVE_LOG_TAG, "[CodePush] " + message);
-    }
-
-    public static void logBundleUrl(String path) {
-        log("Loading JS bundle from \"" + path + "\"");
+    public static void writeReadableMapToFile(ReadableMap map, String filePath) throws IOException {
+        JSONObject json = CodePushUtils.convertReadableToJsonObject(map);
+        String jsonString = json.toString();
+        FileUtils.writeStringToFile(jsonString, filePath);
     }
 }
diff --git a/android/app/src/main/java/com/microsoft/codepush/react/FileUtils.java b/android/app/src/main/java/com/microsoft/codepush/react/FileUtils.java
new file mode 100644
index 0000000..113df51
--- /dev/null
+++ b/android/app/src/main/java/com/microsoft/codepush/react/FileUtils.java
@@ -0,0 +1,179 @@
+package com.microsoft.codepush.react;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+public class FileUtils {
+
+    public static final int WRITE_BUFFER_SIZE = 1024 * 8;
+
+    public static void copyDirectoryContents(String sourceDirectoryPath, String destinationDirectoryPath) throws IOException {
+        File sourceDir = new File(sourceDirectoryPath);
+        File destDir = new File(destinationDirectoryPath);
+        if (!destDir.exists()) {
+            destDir.mkdir();
+        }
+
+        for (File sourceFile : sourceDir.listFiles()) {
+            if (sourceFile.isDirectory()) {
+                copyDirectoryContents(
+                        CodePushUtils.appendPathComponent(sourceDirectoryPath, sourceFile.getName()),
+                        CodePushUtils.appendPathComponent(destinationDirectoryPath, sourceFile.getName()));
+            } else {
+                File destFile = new File(destDir, sourceFile.getName());
+                FileInputStream fromFileStream = null;
+                BufferedInputStream fromBufferedStream = null;
+                FileOutputStream destStream = null;
+                byte[] buffer = new byte[WRITE_BUFFER_SIZE];
+                try {
+                    fromFileStream = new FileInputStream(sourceFile);
+                    fromBufferedStream = new BufferedInputStream(fromFileStream);
+                    destStream = new FileOutputStream(destFile);
+                    int bytesRead;
+                    while ((bytesRead = fromBufferedStream.read(buffer)) > 0) {
+                        destStream.write(buffer, 0, bytesRead);
+                    }
+                } finally {
+                    try {
+                        if (fromFileStream != null) fromFileStream.close();
+                        if (fromBufferedStream != null) fromBufferedStream.close();
+                        if (destStream != null) destStream.close();
+                    } catch (IOException e) {
+                        throw new CodePushUnknownException("Error closing IO resources.", e);
+                    }
+                }
+            }
+        }
+    }
+
+    public static boolean createFolderAtPath(String filePath) {
+        File file = new File(filePath);
+        return file.mkdir();
+    }
+
+    public static void deleteDirectory(File directory) {
+        if (directory.exists()) {
+            File[] files = directory.listFiles();
+            if (files != null) {
+                for (int i=0; i<files.length; i++) {
+                    if(files[i].isDirectory()) {
+                        deleteDirectory(files[i]);
+                    }
+                    else {
+                        files[i].delete();
+                    }
+                }
+            }
+        }
+        directory.delete();
+    }
+
+    public static void deleteDirectoryAtPath(String directoryPath) {
+        deleteDirectory(new File(directoryPath));
+    }
+
+    public static void deleteFileAtPathSilently(String path) {
+        deleteFileSilently(new File(path));
+    }
+
+    public static void deleteFileSilently(File file) {
+        if (!file.delete()) {
+            CodePushUtils.log("Error deleting file " + file.getName());
+        }
+    }
+
+    public static boolean fileAtPathExists(String filePath) {
+        return new File(filePath).exists();
+    }
+
+    public static String readFileToString(String filePath) throws IOException {
+        FileInputStream fin = null;
+        BufferedReader reader = null;
+        try {
+            File fl = new File(filePath);
+            fin = new FileInputStream(fl);
+            reader = new BufferedReader(new InputStreamReader(fin));
+            StringBuilder sb = new StringBuilder();
+            String line = null;
+            while ((line = reader.readLine()) != null) {
+                sb.append(line).append("\n");
+            }
+
+            return sb.toString();
+        } finally {
+            if (reader != null) reader.close();
+            if (fin != null) fin.close();
+        }
+    }
+
+    public static void unzipFile(File zipFile, String destination) throws IOException {
+        FileInputStream fileStream = null;
+        BufferedInputStream bufferedStream = null;
+        ZipInputStream zipStream = null;
+        try {
+            fileStream = new FileInputStream(zipFile);
+            bufferedStream = new BufferedInputStream(fileStream);
+            zipStream = new ZipInputStream(bufferedStream);
+            ZipEntry entry;
+
+            File destinationFolder = new File(destination);
+            if (!destinationFolder.exists()) {
+                destinationFolder.mkdirs();
+            }
+
+            byte[] buffer = new byte[WRITE_BUFFER_SIZE];
+            while ((entry = zipStream.getNextEntry()) != null) {
+                String fileName = entry.getName();
+                File file = new File(destinationFolder, fileName);
+                if (entry.isDirectory()) {
+                    file.mkdirs();
+                } else {
+                    File parent = file.getParentFile();
+                    if (!parent.exists()) {
+                        parent.mkdirs();
+                    }
+
+                    FileOutputStream fout = new FileOutputStream(file);
+                    try {
+                        int numBytesRead;
+                        while ((numBytesRead = zipStream.read(buffer)) != -1) {
+                            fout.write(buffer, 0, numBytesRead);
+                        }
+                    } finally {
+                        fout.close();
+                    }
+                }
+                long time = entry.getTime();
+                if (time > 0) {
+                    file.setLastModified(time);
+                }
+            }
+        } finally {
+            try {
+                if (zipStream != null) zipStream.close();
+                if (bufferedStream != null) bufferedStream.close();
+                if (fileStream != null) fileStream.close();
+            } catch (IOException e) {
+                throw new CodePushUnknownException("Error closing IO resources.", e);
+            }
+        }
+    }
+
+    public static void writeStringToFile(String content, String filePath) throws IOException {
+        PrintWriter out = null;
+        try {
+            out = new PrintWriter(filePath);
+            out.print(content);
+        } finally {
+            if (out != null) out.close();
+        }
+    }
+}