map tile provider is only an option for android devices. it allows android users to use another map tile provider, mapbox, which allows them to manually download map tiles.
in the solo app, you can't choose your map style in the map view. it defaults to satellite and will display map tiles if you have internets. if you don't have internets and have not cached your map, it will display nothing.
to cache your map, make sure you are connected to the internets and simply open up map view in the solo app and pan to the area you want to cache by moving the map and zooming in/out. the map tiles are cached automagically.
the funny thing is, 'plan your flight' supports standard, satellite and hybrid map views. i don't know why 3DR couldn't be bothered to add standard or hybrid to the map view.