Within my Android application I display some data within a map. To do that I currently download some map data from an OpenStreetMap tile server and store it locally (so that users can access an already used map without causing traffic again).
Now I have seen some Android apps using other map data/sattelite pictures (perhaps from Google?). Unfortunately I could not find any tile servers that offer the same principle like OSM where it is possible to cache the map tiles locally. So does anybody know of similar projects/tile servers that are not OSM but provide the same functionality?