Locate missing items such as keys and backpacks with the Proximo Tag Bluetooth Tracker from Kensington. The free Kensington Proximo app is available for download from iTunes and the Google Play Store. Once installed, the Proximo tag connects to your smartphone via Bluetooth 4.0. Your smartphone can then be used to locate your missing item with a press of a button on the app screen. There is also a proximity meter that provides a distance estimate to your missing item. The tag has a built-in LED visual alert so you can locate it in the dark.