Before revision: Bluetooth low energy beacon Modern key finders use a Bluetooth low energy beacon to broadcast a uniqueID that is picked up by nearby phones running the appropriate software, that is then reported to the manufacturer's website along with the location where they picked up the signal.
After revision: Bluetooth tracking devices that used apps were introduced in 2008 by Chris Herbert, Christian Smith, and Tyler Crain in their presentation at URL The first mass-market Bluetooth tracker was the Cobra Tag released in URLBluetooth low energy beacon Modern key finders use a Bluetooth low energy beacon to broadcast a uniqueID that is picked up by nearby phones running the appropriate software, that is then reported to the manufacturer's website along with the location where they picked up the signal.