here is a link for my application:
description: automatically detect accident and send SMS message to your defined numbers with the location, and also has an option to call a predefined number (ex: emegrency services).
how does it do it:
when you enter your car you must manually activate the background service which uses the accelerometer to detect a gforce measurement above some maximum defined threshold. on the main activity UI the maximum g-force in an interval of 4 seconds is shown on a gauge. if the service detects an accident it launches an activity that determines if the measurement was a false alarm or it is valid. if it determines a valid reading it starts to ring and vibrate to a chosen ringtone and if you don't cancel it during that period it launches the messages and gives you the call option.
well and the most important part safety comes free of charge! so try it and i hope you like it.