Our map data comes from the OpenStreetMap (OSM) community mapping project which has excellent coverage in many places, but less detail in some other places. You can view the map detail on their website (http://www.openstreetmap.org or for cycling at http://www.opencyclemap.org), and even contribute to it by adding missing content. Many of the other map apps available on the App Store are also based on OSM and will have the same level of detail as PocketEarth. The great thing about the OSM project is that anyone can contribute to help improve it. If you have some time and interest, you can read more on their website http://wiki.openstreetmap.org/wiki/Beginners%27_guide.