Return to root view controller from multiple modal presentations or segues (Xcode for iOS)

If you are returning to the root view controller from a series of modally presented view controllers then the following code will work in iOS6

[self.view.window.rootViewController dismissViewControllerAnimated:YES completion:nil];

In iOS5 it would be

[self.view.window.rootViewController dismissModalViewControllerAnimated:YES];

If you want to dismiss all modally presented view controllers from the App Delegate, for example from

- (void)applicationWillResignActive:(UIApplication *)application

then you'd write

[self.window.rootViewController dismissViewControllerAnimated:NO completion:nil];

Or for iOS5

[self.window.rootViewController dismissModalViewControllerAnimated:NO];