A smartphone app where overprotective moms can stalk their kids. It uses the signal given off by their phones to track their every movement. They are, however, easy to trick. If you go off somewhere, leave your phone with a friend. However, the app is actually quite useless because if a rapist kidnaps your child, then they will probably be prepared for the app and leave the phone somewhere.
Rapist: o yea, look at this kid i just kidnapped! o shit hes got family locator. ill just leave his phone in the mall somewhere. i beat the system, woot!