The alarm sound is to much silent, because of iPhone speaker sound capacity. This APP works when the phone is on only - your battery will be consumed fast or if someone put it in sleep mode you can say goodbye iPhone. The "proximity sensor" only works at very high sensitivity (about 97%) at my mobile. Despite these drawbacks, the functionalities presented here works nicelly. To improve this APP I sugest the developers to include a messager functionality, sending the mobile GPS position hourly If an internal security code is not disarmed.