Allow location all the time
The one setting a location-sharing app needs.
Open Menu → Location permission to check what your phone allows.
- Allowed all the time: sharing keeps working when the app is in the background. This is what you want.
- Allowed while using the app: your circle only sees you while ZoneCircle is open.
- Not allowed: ZoneCircle can't see your location, so it can't share it.
To change it, open your phone's Settings → Apps → ZoneCircle → Location, choose Allow all the time, and turn on Use precise location. Approximate location can be kilometres off.