Not sure but isn't that just like the TAG. It really would not work for a UAV as to get any distance you are required to be around other users that have smart phone connectivity.
On its own I think its just a short range device and only gains range if around other users that happen to be close enough to be connected.
EDIT just found this on their site.
TrackR devices will stay connected with your phone up to 100 feet, conditions may vary in range. After the 100 feet, the TrackR device will disconnect and record your last known GPS location on a map located in the TrackR App.
However, Crowd GPS enables you to find your items after they have been lost. When an item goes missing with a TrackR device attached, all TrackR enabled phones will begin to search for that item. When another user comes nearby the lost item, that user's phone will anonymously ping our server to update the items item's owner with new GPS coordinates of when & where it was last seen. We currently have the largest active Crowd GPS network and we are constantly building this network so the updates become more real time, ensuring any item will be found.