I want one that's not tied to the phone since my phone is what I usually need to find or gets left behind outside. So I want a small keychain-able device that

I want one that's not tied to the phone since my phone is what I usually need to find or gets left behind outside. So I want a small keychain-able device that alerts or vibrates when my stick-on device, eg. phone is > some distance away. EDIT: Just read the updates, it has it, nice! We have added a new app feature: Reverse Virtual Leash: You put a Sticker on your keys etc, if you forget your phone behind, the sticker on keys will buz. You have to have the SticNFind app runnig on the backround for the reverse Virtual leash to work. This will work on both iPhone and Android. But remember, you must have the app running on the background, which usually, if you launch an app, is stays on the background unless you close it.