The Topo Germany can be combined with all other AirMap products. The technology used in AirMap allows seamless flights between the topographic maps. If on a flight outside of the area of Topo Austria no adjoining Topo map (Switzerland, Austria etc.) is available,  then AirMap will switch automatically to any available Topo map or if GXP is installed to a satellite map.  I.e. not only the map parts are automatically loaded, but the crossing from one to the other map occurs without interruption. No borders visible when crossing boundaries from one to another adjacent map.