Although I have yet to get a GPS (I'm waiting a few more months, to see exactly what will happen with my current vehicle situation - whether I decide to keep her, for likely a decade to come, or, alternatively, get new - as any new vehicle I get will likely come pre-packaged with GPS) nor have a compatible phone for use with their system, I have already taken advantage of the full set of offerings from the Trapster service, as well as uploaded my area's (Cleveland, near-eastern suburbs) traps to their TrapMap.
Currently, it doesn't seem that there are that many users of the system in NE-Ohio, at least not in the Cleveland-Metro area.
Of the traps that I entered, none have yet been cross-confirmed.
And as for those that were entered (for my immediate area) prior to my participation on that website, there were only a few, all entered by the same motorist/driver (which, of-course, I cross-confirmed).
Hopefully, this system will catch-on in our area. happya$$
, you're out on the west-side, right?