https://f-droid.org/packages/com.google.android.gms backend that uses local GSM data to resolve user

location.

A facility in the setting menu allows you to create a database using data from

<a href="http://opencellid.org">OpenCellId</a> and/or <a href="https://location.services.mozilla.com

Mozilla">Location Services</a> CSV files. Alternatively, the on-phone database can

be generated in advance via the <a href="https://github.com/n76/lacells-creator">lacells-creator</a> scripts that gather tower information from those two sources,

too.

This backend performs no network data. All data acquired by the phone stays on

the phone and no queries are made to a centralized AP location provider.

User