I went for Tasker.
Not heard of Tasker before, but now installed and got a few profiles set up.
If a new sim is inserted in my phone, it now texts my wife with the new number, GPS co-ordinates and emails me a picture of who turned on the phone. With the new number, I can text the phone to obtain updates on GPS location and when near the phone, can text it to turn the volume up and start making some noise.
Looking forward to playing with it further and exploring the other plug-in apps for it.
Thanks for the app suggestion