The Good: A perfect square, the Nokia Treasure Tag has a logical design and app. It works for Android, iOS, and Windows Phone. The Bad: The tracker is a little chunky for my keychain, doesn't illuminate like some competitors, and had trouble reconnecting during my testing. The Bottom Line: The Nokia Lumia Treasure Tag is about the right price for what it does, but people who are serious about keeping tags on their possessions should seek a smaller device that does more. A flip of the stomach, a furrow of your brow. The moment you realize you've misplaced your key or wallet or phone or anything you really, really need is a moment you wish you had the Nokia Treasure Tag, or something like it.The small, 1.2-inch square device (30mm) measures 0.4 inch thick (10mm) and weighs 0.46 ounces (13 grams). The 22omAh battery promises a maximum standby time of 180 days, or about 6 months. You're able to replace the battery on your own.Globally sold in yellow, cyan, white, and black, the Treasure Tag is a simple tool that pairs to your smartphone through Bluetooth (low-energy) or NFC. Each package comes with two rubberized bands that snap into the tracker's grooved perimeter. One comes with a loop, for attaching to keys or perhaps your bike's handlebars. The other band is smooth and protrusion-free, creating a lower profile if you'd rather slip it into something. You'll pair, set up, and manage your up to four Treasure Tags through a mobile app. Although it's branded as a Nokia product, the Treasure Tag will work with Android and iOS phones in addition to Windows Phones. Here, you're able to set your notifications and tones, and look up your Tag's last known whereabouts on a map.Check out the gallery above for a full step-by-step setup.Now, the Treasure Tag, like other similar devices, is bidirectional, which means that if you know where the tag is, but lost track of your phone, pressing the single button in the center of the tag will make your handset chirp, assuming you're within the approximately 130-foot Bluetooth range (roughly 40 meters).How well does it work? Most of the time, the Treasure Tag worked, alerting me whenever I fell out of Bluetooth range with the device. I'd probably turn that feature off if I used it full-time, and let the device run passively, only using it when I really needed it.