The Tile is a small, matchbook-sized Bluetooth device that works in conjunction with a mobile app to provide its location. The main purpose of the Tile is to help you keep track of the items to which it is attached. It is small enough to place on your key chain or put on your pet's collar. (My dog has one.) The device is waterproof and permanently sealed, so replacing the battery is not possible. The manufacturer promises a one year battery life, and as my set of tiles is approaching the one year mark, this appears to be accurate. The company has a "reTile" program to replace and recycle tiles at a discount after 11 months.
Setup is easy - the IOS or Android app walks you through the process. Using the app, you can monitor the location of the tiles - with a few restrictions. Mainly, the Tile needs to be within about 100 feet of your phone, although mine seems to top off at about half that distance. You can instruct the Tile to play a tune to aid you in locating it, however the sound is not very loud.
One interesting note is that the Tile can utilize a sort of "mesh" network to locate missing tiles. In this mode, any mobile device that is running the Tile app will report the location of your Tile if it gets within range, without telling the device's user about your Tile. The effectiveness of this feature of course depends on how many people in the vicinity of your lost Tile are running the app. Luckily, I've never had to test this. Another feature I like is the ability to share Tile locations with another user.
Tiles run about $15 - $25 each depending on the quantity ordered. They work well for finding an item misplaced in your home or within a defined area. If you are trying to locate a Tile lost a few towns away, your success will depend on whether someone running Tile app comes close enough to your Tile to detect it. In many places that may never happen. Visit TheTileApp.com