What I’ve Got: tile

Tile is a tiny Bluetooth tracker and easy-to-use app that finds your phone, keys, and anything you don’t want to lose-in seconds. Once you attach a Tile to an item, and you can locate it by sound, by seeing its last known location on a map, or by marking it as “lost” and getting an alert when it’s found.

This can be attached to whatever you want because it is such a simple design with tiny size.