What if the app receives GPS and calculates speed and so on but the map stays blank?
Please click in the map area and change the zoom level. You can also center the map to your location with the button in the upper right corner of the map. In case it still stays blank you should delete the app and reinstall it. The server where the app loads the map data could have been down so you might loaded blank map tiles and now they are stored in the map cache.
