WatchKit is a new framework to build apps for Apple watch. To run third-party apps on Apple watch, you need the watch to be connected to the iPhone. WatchKit helps you create apps for Apple watch by creating two targets in Xcode:
The WatchKit app: The WatchKit app is an executable app to be installed on your watch, and you can install or uninstall it from your iPhone. The WatchKit app contains the storyboard file and resources files. It doesn't contain any source code, just the interface and resource files.
The WatchKit extension: This extension runs on the iPhone and has the
InterfaceControllersfile for your storyboard. This extension just contains the model and controller classes. The actions and outlets from the previous WatchKit app will be linked to these controller files in the WatchKit extension.
These bundles—the WatchKit extension and WatchKit app—are put together and packed inside the iPhone application. When the user installs the iPhone app, the system will prompt the...