Natasha Murashev (aka NatashaTheRobot):
“The WatchKit SDK is still very basic, and the hardest part is getting information from your iPhone app to the watch and sharing data in between the two. Most of the code logic happens on the phone, and things on your watch will be very static. The basic architecture you’ll be working with is having most of the code in the WatchKit extension and having to share data between your devices.”
In this video, Natasha discusses data sharing via NSUserDefaults, NSFileCoordinator, Frameworks and the Keychain.