diff --git a/Libraries/AppRegistry/AppRegistry.js b/Libraries/AppRegistry/AppRegistry.js
index f36f88132..157cbaa37 100644
--- a/Libraries/AppRegistry/AppRegistry.js
+++ b/Libraries/AppRegistry/AppRegistry.js
@@ -74,7 +74,9 @@ var AppRegistry = {
     );
     invariant(
       runnables[appKey] && runnables[appKey].run,
-      'Application ' + appKey + ' has not been registered.'
+      'Application ' + appKey + ' has not been registered. This ' +
+      'is either due to a require() error during initialization ' +
+      'or failure to call AppRegistry.registerComponent.'
     );
     runnables[appKey].run(appParameters);
   },
diff --git a/Libraries/JavaScriptAppEngine/System/JSTimers/JSTimers.js b/Libraries/JavaScriptAppEngine/System/JSTimers/JSTimers.js
index 6434541bb..72e75f813 100644
--- a/Libraries/JavaScriptAppEngine/System/JSTimers/JSTimers.js
+++ b/Libraries/JavaScriptAppEngine/System/JSTimers/JSTimers.js
@@ -60,14 +60,10 @@ var JSTimers = {
     var freeIndex = JSTimers._getFreeIndex();
     JSTimersExecution.timerIDs[freeIndex] = newID;
     JSTimersExecution.callbacks[freeIndex] = function() {
-      var startTime = Date.now();
-      var ret = func.apply(undefined, args);
-      var endTime = Date.now();
-      RCTTiming.createTimer(newID, Math.max(0, duration - (endTime - startTime)), endTime, false);
-      return ret;
+      return func.apply(undefined, args);
     };
     JSTimersExecution.types[freeIndex] = JSTimersExecution.Type.setInterval;
-    RCTTiming.createTimer(newID, duration, Date.now(), /** recurring */ false);
+    RCTTiming.createTimer(newID, duration, Date.now(), /** recurring */ true);
     return newID;
   },
 
diff --git a/Libraries/ReactNative/createReactNativeComponentClass.js b/Libraries/ReactNative/createReactNativeComponentClass.js
index c821cfa75..65af58d5e 100644
--- a/Libraries/ReactNative/createReactNativeComponentClass.js
+++ b/Libraries/ReactNative/createReactNativeComponentClass.js
@@ -36,6 +36,7 @@ var createReactNativeComponentClass = function(
   };
   Constructor.displayName = viewConfig.uiViewClassName;
   Constructor.prototype = new ReactNativeBaseComponent(viewConfig);
+  Constructor.prototype.constructor = Constructor;
 
   return Constructor;
 };
diff --git a/React/Executors/RCTContextExecutor.m b/React/Executors/RCTContextExecutor.m
index f585edc10..3a2208739 100644
--- a/React/Executors/RCTContextExecutor.m
+++ b/React/Executors/RCTContextExecutor.m
@@ -66,7 +66,6 @@
 {
   RCTJavaScriptContext *_context;
   NSThread *_javaScriptThread;
-  JSValueRef _undefined;
 }
 
 /**
@@ -238,9 +237,6 @@ static NSError *RCTNSErrorFromJSError(JSContextRef context, JSValueRef jsError)
         JSContextGroupRelease(group);
       }
 
-      // Constant value used for comparison
-      _undefined = JSValueMakeUndefined(ctx);
-
       strongSelf->_context = [[RCTJavaScriptContext alloc] initWithJSContext:ctx];
       [strongSelf _addNativeHook:RCTNativeLoggingHook withName:"nativeLoggingHook"];
       [strongSelf _addNativeHook:RCTNoop withName:"noop"];
@@ -312,7 +308,7 @@ static NSError *RCTNSErrorFromJSError(JSContextRef context, JSValueRef jsError)
     JSValueRef requireJSRef = JSObjectGetProperty(contextJSRef, globalObjectJSRef, requireNameJSStringRef, &errorJSRef);
     JSStringRelease(requireNameJSStringRef);
 
-    if (requireJSRef != NULL && requireJSRef != _undefined && errorJSRef == NULL) {
+    if (requireJSRef != NULL && !JSValueIsUndefined(contextJSRef, requireJSRef) && errorJSRef == NULL) {
 
       // get module
       JSStringRef moduleNameJSStringRef = JSStringCreateWithCFString((__bridge CFStringRef)name);
diff --git a/React/Modules/RCTAppState.m b/React/Modules/RCTAppState.m
index 8c46655c6..cf8f95910 100644
--- a/React/Modules/RCTAppState.m
+++ b/React/Modules/RCTAppState.m
@@ -48,17 +48,16 @@ RCT_EXPORT_MODULE()
     for (NSString *name in @[UIApplicationDidBecomeActiveNotification,
                              UIApplicationDidEnterBackgroundNotification,
                              UIApplicationDidFinishLaunchingNotification]) {
-
       [[NSNotificationCenter defaultCenter] addObserver:self
                                                selector:@selector(handleAppStateDidChange)
                                                    name:name
                                                  object:nil];
-
-      [[NSNotificationCenter defaultCenter] addObserver:self
-                                               selector:@selector(handleMemoryWarning)
-                                                   name:UIApplicationDidReceiveMemoryWarningNotification
-                                                 object:nil];
     }
+
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(handleMemoryWarning)
+                                                 name:UIApplicationDidReceiveMemoryWarningNotification
+                                               object:nil];
   }
   return self;
 }
diff --git a/React/Modules/RCTUIManager.m b/React/Modules/RCTUIManager.m
index 636df0406..127cbd9fc 100644
--- a/React/Modules/RCTUIManager.m
+++ b/React/Modules/RCTUIManager.m
@@ -197,7 +197,8 @@ static UIViewAnimationCurve UIViewAnimationCurveFromRCTAnimationType(RCTAnimatio
   NSMutableDictionary *_defaultViews; // Main thread only
   NSDictionary *_viewManagers;
   NSDictionary *_viewConfigs;
-  NSUInteger _rootTag;
+
+  NSMutableSet *_bridgeTransactionListeners;
 }
 
 @synthesize bridge = _bridge;
@@ -263,7 +264,8 @@ static NSDictionary *RCTViewConfigForModule(Class managerClass, NSString *viewNa
     // Internal resources
     _pendingUIBlocks = [[NSMutableArray alloc] init];
     _rootViewTags = [[NSMutableSet alloc] init];
-    _rootTag = 1;
+
+    _bridgeTransactionListeners = [[NSMutableSet alloc] init];
   }
   return self;
 }
@@ -287,6 +289,7 @@ static NSDictionary *RCTViewConfigForModule(Class managerClass, NSString *viewNa
     _rootViewTags = nil;
     _shadowViewRegistry = nil;
     _viewRegistry = nil;
+    _bridgeTransactionListeners = nil;
     _bridge = nil;
 
     [_pendingUIBlocksLock lock];
@@ -397,6 +400,10 @@ static NSDictionary *RCTViewConfigForModule(Class managerClass, NSString *viewNa
         [(id<RCTInvalidating>)subview invalidate];
       }
       registry[subview.reactTag] = nil;
+
+      if (registry == _viewRegistry) {
+        [_bridgeTransactionListeners removeObject:subview];
+      }
     });
   }
 }
@@ -482,7 +489,6 @@ static NSDictionary *RCTViewConfigForModule(Class managerClass, NSString *viewNa
   }
 
   // Perform layout (possibly animated)
-  NSNumber *rootViewTag = rootShadowView.reactTag;
   return ^(RCTUIManager *uiManager, RCTSparseArray *viewRegistry) {
     RCTResponseSenderBlock callback = self->_layoutAnimation.callback;
     __block NSInteger completionsCalled = 0;
@@ -547,17 +553,11 @@ static NSDictionary *RCTViewConfigForModule(Class managerClass, NSString *viewNa
     }
 
     /**
-     * Enumerate all active (attached to a parent) views and call
-     * reactBridgeDidFinishTransaction on them if they implement it.
-     * TODO: this is quite inefficient. If this was handled via the
-     * ViewManager instead, it could be done more efficiently.
+     * TODO(tadeu): Remove it once and for all
      */
-    UIView *rootView = _viewRegistry[rootViewTag];
-    RCTTraverseViewNodes(rootView, ^(id<RCTViewNodeProtocol> view) {
-      if ([view respondsToSelector:@selector(reactBridgeDidFinishTransaction)]) {
-        [view reactBridgeDidFinishTransaction];
-      }
-    });
+    for (id<RCTViewNodeProtocol> node in _bridgeTransactionListeners) {
+      [node reactBridgeDidFinishTransaction];
+    }
   };
 }
 
@@ -844,6 +844,10 @@ RCT_EXPORT_METHOD(createView:(NSNumber *)reactTag
         view.layer.allowsGroupOpacity = YES; // required for touch handling
       }
       RCTSetViewProps(props, view, uiManager->_defaultViews[viewName], manager);
+
+      if ([view respondsToSelector:@selector(reactBridgeDidFinishTransaction)]) {
+        [uiManager->_bridgeTransactionListeners addObject:view];
+      }
     }
     viewRegistry[reactTag] = view;
   }];