I like osmand for off-grid motorcycle type stuff but I’ve found it to be somewhat useless for final mile navigation especially ironically in the city. I still use it as it’s awesome and allows pre-planned offline routes but I also still use gmaps as well. When I drove trucks for a living I found that the Garmin (truck specific but buy what you need) GPS to be quite amazing and will probably buy one of those for my car someday.
Generally you can sign up this person for many types of annoying mail by doing essentially just that