Not sure the iPhone is a suitable platform for this

On my recent trip up to Yosemite, the GPS went nuts a good hour of the time as we approached the Sierras. Insufficient signal? Maybe. Often, TomTom told us we were somewhere else -- another road, in the middle of nowhere -- and sometimes it thought we were going the opposite direction of what were were. (That was strange.)

The software needs increased stickiness -- "I will never leave the road". It also needs to smooth things out -- if it is clear that the signal is weak, maybe it should be more suspicious of radical vhanges of location. "Hmm, user jumped from one highway to another, in spite of the fact that he has not yet reached the exit from one to the other ... I dont think so."

Also, I am missing an off button. When I close the app, does it still do something? (Or did it just save the location and start again when the app powers up?) Would be great to integrate with Yelp. "You want to go to a really nice restaurant? We will show them on the map."

//M// about TomTom U.S. & Mexico