CarGuard provides security for your parked car. (Japanese click here)

The app can run on your old iPhone after you have upgraded to a newer model.
CarGuard calls to a registered phone number are triggered by any major tilt or positional change for the old iPhone, based on the accelerometer's ability to pinpoint its location in three dimensions.
If there is a thief in the car, you can challenge him with a shout of "What are you doing?"

Put your old iPhone in your parked car and push the START button on the CarGuard touch screen.
This activates the accelerometer, which disregards data from the first 20 readings, and generates an average from the next 20 readings to define its 3D base location.
Monitoring is then initiated, and it is stopped and re-initiated at one-minute intervals thereafter until the specified End Time.
Setting the screen to a low brightness conserves the battery.

When active, the monitoring screen displays location on three-dimensional axes (X, Y, and Z).
Some older iPhones always display the location as 0.000000. In that case, please use another iPhone.

If your car moves, the accelerometer detects the altered location, and you can be sure of getting the news with a call from CarGuard.