TrackR Bravo: This quarter-sized device will make sure you find your misplaced keys in no time. Using its app you can quickly locate your misplaced items in seconds. Its distance indicator lets you know how far away you are from your items and finds the exact location. If you can't see them (hidden under the couch), then just make it ring by a tap on your smartphone. You can use its 2-way finding capabilities to find your phone, just press the button on your TrackR, and your phone will ring. It's supported by Crowd GPS Network, which makes things a lot easy if you happen to leave behind your keys. You can track multiple items on its app and its fully customizable that means you set the app to ring a certain tone when you leave something behind. Its app is compatible with iPhone and Android smartphones. It has many more uses apart from keeping track of your keys, use it to find purses, iPads, and more.