Turn your old Android phone into a car theft alarm and use this application, Car Theft Alarm Control, for controlling the alarm device.
The basic alarm features are totally free and you can buy some extra features if you wish!
- Detect location of your car - Geofencing - Battery alerts - Shock detection - Car Live Tracking - Route To Car - Share your car's location - Support for multiple users - Support for Bluetooth connection - Support for GPRS (TCP) connection
In addition to this app you need an alarm application, Car Theft Alarm, to be installed to another Android phone. You can find it here: https://play.google.com/store/apps/details?id=akira4apps.carthieftracker