I have been running just with my watch and the Apple activity tracker.
But I wanted to calibrate it so tonight I ran with my iPhone too.
I tried to use the Nike+ app and the Activity app both starting them on my watch. I ran with the activity app on screen.
When I was done I stopped the activity app and went to the Nike + app, but it had stopped.
So can you run the activity app and a different running app at the same time. Or do you need to start the other app on your phone and the activity on your watch?