watchOS SDK Release Notes for watchOS 2
watchOS SDK 2.0 provides support for developing watchOS apps. It is packaged with a complete set of Xcode tools, compilers, and frameworks for creating apps for watchOS. These tools include the Xcode IDE and the Instruments analysis tool, among many others.
This version of watchOS is intended for installation only on devices registered with the Apple Developer Program. Attempting to install this version of watchOS in an unauthorized manner could put your device in an unusable state.
For issues not mentioned in the Notes and Known Issues section, please file bugs through the Apple Developer website (https://developer.apple.com/bug-reporting/ios/). Additionally, you may discuss these issues and watchOS SDK 2.0 in the Apple Developer Forums.
Notes and Known Issues
Activation Lock is enabled on your Apple Watch if you have Find My iPhone enabled on your iPhone.
Enable "Install All Apps" in Watch.app -> General -> App Install for WatchConnectivity to work correctly during Build and Run cycles.
Keychain items created on an Apple Watch are not viewable on an iOS device.