It worked for an East Bay woman. A mugger stole her iPhone in San Leandro and the app found it in Oakland.
Police said the app called "Find My iPhone" was the key to recovering her stolen device. The woman had downloaded the app for free onto her iPhone and she is really glad she did that.
It works by sending out a GPS signal. San Leandro police used it to pinpoint the phone's location and arrested the man who had it.
It also works for iPads and there are similar apps for Android phones.