Where Is My Phone? (W.I.M.P.) 1.2   
by W.I.M.P. Software   

This security application runs silently on your device. In the event of the phone being stolen or lost, simply send a special SMS text to the phone and W.I.M.P. will silently intercept the message and report back the phone's GPS location in a format which can easily be tracking using any common mapping application.
W.I.M.P. will also automatically detect if the SIM card has been changed and send you the new number allowing you to ring or track the device.
W.I.M.P runs upon device startup and remains active in the background at all times.