Radiocells.org UnifiedNlp Backend

https://f-droid.org/packages/com.google.android.gms wifi/cell geolocation backend that uses
Radiocells.org database for geolocation.

Location can be retrieved either online or completely offline if a local
database is already present.

https://f-droid.org/packages/org.openbmap can be used to gather wifi and cell information.