Best to try those location apps with the GPS off and see what results you get before you actually need them. I have not had much luck with them. However, if you have location services enabled, Cerberos can locate your phone. A thief can quickly switch off GPS. But it will take more of a determined effort to turn off location services. Or so I've read.
I recently switched from Lookout to Cerberos because of this. I've also started leaving the GPS on all the time having learned that the GS4 will not excessively drain the battery by doing so. The GPS is only tasked when needed.