There's an app for that.
In fact, police in Boulder, Colorado, report a man used two different apps on his iPhone to help catch a crook.
A local television station reports Hugh Huffaker left his cell phone in a locker at a rec center and when he returned, it was gone.
Huffaker used a GPS tracking app to trace his iPhone to the Boulder Public Library.
When he got to the library, he used a second app to make the phone alarm go off.
Officers say they arrested a homeless man on suspicion of theft and burglary.