Mobile Tracker FREE lets you locate mobile phones from any provider using the latest GPS location technology - as long as the other mobile phone is very close to you! : -) Be aware: This is the best joke ever! Show the app to friends and tell them you are able to locate their phone. Enter the number and show them how the app locates them.
The will be scared as hell. Of course the app cannot locate other phones but only yours. However, as your friend is standing next to you for this joke it is guaranteed to work 100% .