This is an iOS version of Mobility for Android. Android Mobility uses gps, wifi, cell tower info, and accelerometer data to classify a user's activity. In addition doing activity classification on device, it makes it's data available to the Ohmage Android client for upload to Ohmage server.
Since iOS background processing is limited, Mobility will track as much info as possible, but not attempt classification on device. It will make it's data available to other apps. The extent to which activity classification can be done on the server is TBD.