Of all the apps in the App Store, this is one that every iPhone owner should download.
If you misplace your phone, Apple’s Find My iPhone app will pinpoint its location on a map. What’s more, if your phone is buried in the couch cushions, the app will instruct your handset to blast a sound for two minutes at full volume — even if it’s set on silent mode. And in the unfortunate event that your phone gets stolen, Find My iPhone can remotely cause the personal data in your phone’s storage to self destruct.
Link: Find My iPhone