Microsoft's two-step verification app, Microsoft Authenticator, will be one of the latest apps to leave the watchOS App Store. The company will release an update next month to remove the companion app for watchOS. According to Microsoft, the Apple Watch operating system is "incompatible with Authenticator security features." If you already have the app on your Apple Watch, you'll still need to delete it since it won't work after January. The iPhone and iPad versions of the app will still be available for iOS users.