[novok]

I don't know if openstreetmaps provides a free tile server, but I could see that as an option for the more privacy minded. Or to preload a basic map so your not querying a tile server, and to go even further, preload a more detailed map like older offline GPS apps.

In the iOS app you can also add an option to use apple maps instead too.

[myself248]

You're not supposed to use OSM's free servers in production, and the options for running your own are assembly-required to such a degree that I can't even assess how far beyond my own skills they lie.