tower — Open Source Navigation App

GPL-3.0-or-later

no Google Services dependencies, only necessary permissions (fine and coarse location, internet, foreground service)
connects to several online map providers
acceptable performance on slow GPRS-EDGE networks; may find coarse location by phone cell without GPS; may create waypoints with GPS without phone and internet connections
displays and saves cell info ( MCC, MNC, LAC, CID ) and the signal strength ( RSRP/dBm )
all waypoints are stored on a memory card and may be organized in any number of files (by regions etc.)
waypoint lists may be exported or imported in the GPX format, compatible with many navigators and software
finds location only by explicit user's command, so is very mild on the battery
capable of writing tracks (by means of a foreground service) and exporting them in the GPX format
tracks from other devices (GPX files) may be viewed along with your data
NOT implemented: map offline caching, routing, editing tracks, photo and video attachments, serving cold beer :)
for pure open distributions, that lack API keys and access to some services, there are options to enter user's own keys

Install

F-DroidGitHub