Not sure of a FOSS for this, but the one I’ve been using for over 10 years across iPhone and Android was Navmii.
This is a must have for any long driving trips because unlike Google Maps, Apple Maps, etc. that require an internet connection or you to manually download specific sections for offline use, this one allows you to download entire areas for offline use and just uses the GPS for guidance.
Speaking as someone from the US, I use it to download entire US states so that I will have that entire state when traveling. Helps a lot if in an area like the desert or somewhere secluded where cell reception is limited or non-existent. Doesn’t have all the fancy POIs but does have the roads to help you navigate out of being lost.
Would be nice to have a FOSS alternative, but this works. I think you do need to have a free account, but it doesn’t cost anything. I’ve spent $0 on it but have used it a lot.