Geofence is a virtual fence (a circle around certain location) that you can preset online. When the phone enters/leaves the fence, you receive an alert via email or phone SMS message.

For example, you set a geofence named "School" as a 3000 feet circle from the center of the school. When your child carrying the phone leaves this circle, you receive an Email or SMS saying "Joe leaves school at 5:30PM".

Note: the geofence alerts are triggered when the phone location is fixed and sent to the server online. In most cases, the GPS location is not calculated when the phone is right crossing the fence, so they are triggered at the next GPS fixing time after crossing the fence. The delay is usually less than the auto data sending interval set in the software settings.

Don't set the fence radius less than 500 feet because with small fences the GPS signal fluctuation may trigger false alarms.

You can setup fences in either of the two ways:
1). From your "Tracking" or "History" page, click "Set" in the "Fence" column of the GPS data table.
2). Go to your "Account" page, then click "Manage Fences" link.