Not really an auto trigger, more like remote trigger ;).
FYI, Contour+2 (and Contour+) also supports remote viewfinder as well as start/stop via Android (bluetooth) & IoS (not sure if the phone needs an extra connector or not) straight from the manufacturer. It would be pretty nice to have some kind of Harry's Lap Timer integration, though.
The GPS output from the Contour+ works great w/ the ChaseCam DashWare software as well.
So you question is if it is possible to start the camera later, not when the app is started? The reason I start it early currently is a) it is the only way to detect it is connected I'm currently aware of (but this will most probably change soon) and b) the camera needs some time from start to recordings the first video. So turning it on when passing the trigger will most probably miss 5 seconds of video in the beginning.