I've just downloaded Navigator, and I'm using it with the OSM maps. I've been trying to test a route, but when I set a departure address, destination and then calculate the route (in the itinerary tab with Route info), I get the error message "Route not found". I'm not looking to navigate, I just want to see the proposed route.
May be CT18 8XX is in an area not accessible to cars. If you move the destination to a road nearby, my Android phone finds a route, but only to the moved destination, not to CT18 8XX.