It's not topo per se, but it can be. It will take any raster map and use it. It has to have an internet connection to get a route, but you can download the route before leaving, and get turn by turn directions while driving it, or you can use your cell phone on a data link for routing on the road. There are a couple of others in development, but AFAIK they don't do routing yet. I haven't kept up that closely, though, so they may be routing by now. Check the Maemo Garage for more info.