I use Blackberry protect and it works perfectly fine...i get a gps lock in about 10 secs or so. It also backups up all my data into a cloud so should i lose my phone i have a backup of my stuff...gives me a loud ringtone if i misplace my phone and the best part is that it allows me to nuke my phone if i lose it or gets stolen.
Cerberus is probably the best Android app for this