A recent temporary loss of an iphone showed the flaws in the Find my Iphone app. Having had a number of devices registered to the Icloud – when one went missing it was an opportunity to test the app for real. However – then you see the issues.
No signal on the device means no chance to get a fix on the device. No history means you have no chance to even work out the rough location of the device. It wouldn’t take much to have the last 10 locations stored so you could get a general direction of travel.
In the end located the iphone which had been handed in. The irony was that where it had been handed into had absolutely zero signal and the messages being sent from the app were only received when the phone had service.