Re the legality of it, have a read of this question and answer answers [here][1]. [1]: http://help.openstreetmap.org/questions/9846/iosmac-app-store-and-cc-by-sa-compatibility

Re the legality of it, have a read of this question and answer [here][1]. [1]: http://help.openstreetmap.org/questions/9846/iosmac-app-store-and-cc-by-sa-compatibility