A quick warning to iPhone users/iPad users to test Find My Phone after installation.
I tested it against an iPhone and an iPad.
The iPhone worked instantly. “OMG Mum, what have you done” howled my daughter.
The iPad (wifi only) however refused to acknowledge the message that was sent until I tethered it to my Android phone. Instantly it was “found” and the messages sent.
So test Find My Phone, check it occasionally to ensure it is keeping track.