I finally had a play with Roadmap+GPSapp, and I think it's pretty cool!

I agree that it would be important to get the zoom levels for the two programs working the same. That's really all that's missing. It's very strange to see them desynchronized on the screen.

Am I imagining things, or is there more latency or "lag" in roadmap than there is when just using GPSapp by itself? By lag I mean that the time between the moment when I press on the brakes and the time that I see my little pointer on the screen actually slow down, seems longer. As well as: seeing an intersection approach in Roadmap, I get the feeling that I've overshot it sooner than I would have if it were just in GPSapp. Any comment on this?