The Apple community has been finding their lost keys since 2021 with the AirTag, but Tile has been helping both Android and Apple users locate their missing devices since 2013. Over a decade later, their latest tracker (after being acquired by Life360), the Tile Mate, is just $16.95 (originally $27.99) for a single tracker, $33.99 (originally $44.99) for a two-pack, and $55.99 (originally $79.99) for a four-pack, the lowest prices, according to price-tracking tools. If you're an Android user, this is a good opportunity to stock up.
(If you're an Apple user, you can use Tiles, but you're better off waiting for the AirTags to drop to $19 to stock up, or get the 4-pack for $69.99 right now; they're much better than Tile's tracker.)
The concept of Tile trackers is the same as AirTags and their usefulness extends to your creativity. Most people use them to find purses, keys, and travel bags, but you can use them to train your dog or as a device to know if people are near a specific spot you want to keep tabs on. (Anyone else want to keep tabs on their abandoned cabin in the woods?)
Once the Tile tracker is outside of Bluetooth range (up to 350 feet in direct line-of-sight conditions, but PCMag's review says it realistically gets about 30 feet), the device uses the Tile community of about 20 million people (according to Tile) to update the location of the tracker by using their phone's Bluetooth. (Apple's community is much larger, with about a billion users, according to Apple).
The back of the Tile Mate has a QR code that people can scan to notify you when they find it. There is a sealed battery inside that is not replaceable that Tile says will last about three years. There is an optional premium subscription that starts at $2.99 per month for more features, if you're interested in that.
