Offline Maps Upgrade Using Themes

GCDroid needs updates to offline maps and themes handling. At the moment the app can't handle many themes and gives just an error message. For example Freizeitkarte and OpenAndroMaps themes won't work at all. Plus there is no access to theme settings at all.

Both are very popular and could be used without problems in other Geocaching apps (C:geo, Locus, Cachebox). It should work in GCDroid too.

https://www.facebook.com/groups/gcdroid/permalink/1128472801440518/