I've turned off a step tracking on my F3 and then on the main screen in GCM a date of last sync is a last day when it was on (I thought it should be last day of sync any of activity as running, biking or so). Moreover a calendar is always showing an info about connection error, and there is no way to see any activities there.. Could be that calendar is somehow connected to step tracking..
1. Log out of the application
2. Force close the application (swipe up on the screen)
3. Clear cache on the phone
a. Press and Hold both the Power and Home buttons at the same time.
b. Release these buttons once the screen goes black and an Apple logo appears.
c. Allow the phone to power on.
4. Re-open the application
5. Re-pair the device if necessary
6. Now attempt to sync
