Comment by brian_cloutier

It does not use system-level facilities that aren't open to normal applications. People love to hate on Google; if they ever embed features into the OS only they are allowed to use you will hear about it very quickly.

There is a class called WifiManager[1] which lets you ask the user to allow background scans. It also lets you see the results of the last scan.

It is unfortunate that the Geofencing APIs are not part of the android platform, but I suppose it's possible they use Google services.

1: http://developer.android.com/reference/android/net/wifi/Wifi...