I often lose my keys I've found what I need. This small key chain (smaller than a car key) allows to geotag the subject (person?) To which it is connected. If it is off, it displays it on a map. If you are near (lost in the house, for example, which happens often, is not it ...) application plays a kind of "you burn / you're frozen": it's almost funny . The initiation, by cons, must be performed by a bar code ... by necessarily very practical. That's the only downside that I find this key chain.
