I want to try the new Apple Watch OS2.
- Opened my existing project
- Added a target
- Changed bundle Identifiers to remove error messages
The Watch App never launches. I get this error message in Xcode after around 5 minutes.

I didn't add any Swift code yet. All I did was add the target and did the above steps.
Anyone else facing similar situations?
I was able to finally get the app on the simulator by going into the Apple Watch app on the iPhone simulator and toggle the switch back and forth.
Experienced same issue and this worked :
make sure watch simulator is selected
go to Hardware menu and chose Home
- click and hold on YourApp to delete it
- after deleting app on watch simulator re-run the app from xcode , it will re-install and work fine.
1.Go to the "Apple Watch" companion app on the iOS simulator.
2.Click your app's name.
3.Toggle "Show App on Apple Watch" switch is on.
4.Run the app again from Xcode.
来源:https://stackoverflow.com/questions/30885799/xcode-7-install-of-apple-watch-application-never-finished