The device works with a companion iOS app. If you don't immediately hear or see your keys after tapping Find in the app, walk around with the app open. Hone has a built-in proximity sensor so you'll know when you're getting closer or farther away.
The project is seeking $46,000 on Kickstarter with 27 days to go. So far about $26,000 has been raised. You can pledge $49 to get one.
Take a look at the video which features Geoffrey Litwack and his sister Kat Dennings (who stars in the popular 2 Broke Girls TV series) describing the device...