I am working on an Android app which makes use of geofence. I want user to decide the radius of geofence. But I want to know what is the minimum and maximum radius for the geofence so that app will work fine.
Maximum- the radius of the earth. GPS is confirmed not to work on the moon.
Minimum- depends on the accuracy of your gps hardware, atmospheric conditions, etc. If everything is great, probably 10 meters reliably. If you fall back to network location, probably about 500 meters.