With the new features and capabilities that watchOS 2 brings to WatchKit, your apps can integrate even more closely with Apple Watch. Take advantage of the Digital Crown, microphone, Taptic engine, and health sensors to take your Apple Watch app to the next level. And with ClockKit, you can extend your app to the clock face with Complications.
watchOS 2 lets applications run natively without being tethered to the iPhone. It was released last September.