Listen for application will enter foreground on WatchKit?

On iOS, I have several ways to know when the user launched my app from the home screen when the app was backgrounded:

• Implement the - applicationWillEnterForeground: in my app delegate.
• Listen to the UIApplicationWillEnterForegroundNotification.

Is there an equivalent in WatchKit? If not, are there any robust alternatives?

The closest you'll find with a WatchKit extension is this set of notifications that were introduced in iOS 8.2:

NSExtensionHostWillEnterForegroundNotification
NSExtensionHostDidEnterBackgroundNotification
NSExtensionHostWillResignActiveNotification
NSExtensionHostDidBecomeActiveNotification

You can read more about these notifications in the NSExtensionContext documentation.