Migrate to OSM or Mapsforge

[carlphilipp]

Context
The F-Droid flavor of the app is using Mapbox right now (while the google-play version uses Google Map).
Mapbox switched their license to be proprietary.
While the current Mapbox SDK used in the app is allowed in F-Droid as it has an open source license, migrating to the latest SDK version will not be allowed.

Description
The app needs to go away from Mapbox:

• I don't know how long the old SDK is going to be maintained.
• I would like to migrate away from jcenter() as it became deprecated last year, but right now it's not possible because Mapbox old SDK is not available in Maven central.

After a quick research in F-Droid forums, it seems like there are two options to replace Mapbox:

• OSM: https://github.com/osmdroid/osmdroid
• Mapsforge: https://github.com/mapsforge/mapsforge

I have not done more research than that, so I don't really know if any of those 2 SDKs contains the features needed/used in the app. I hope so.

[boriguen]

Sounds good, I'll have deeper look shortly!