El Gato released Smart Key, a Bluetooth-enabled device for your keyring that communicates with an app on your iPhone to tell you where your keys are by playing a sound on command, tell you when you've left your keys (or something else) behind, or conversely, when something leaves you. There have been some Kickstarter projects for similar devices, but El Gato's is ready to go now. It's powered by a replaceable battery that the company says lasts six months at a time, and it's compatible with iOS 7, iPhone 4s and up, iPod touch (5th generation), iPad mini, iPad Air, and iPad 3 and 4. It's $39.95.
Check It Out: El Gato's Smart Key Tells Your iPhone Where Your Keys Are
