Gregory's Server@EricCarroll @Julia there are a few, but as Julia mentioned, most navigation apps aren't very geared towards end consumers but there is 'osmand' and 'organic maps' for Android (coverage, accuracy will vary greatly depending how well and complete (many places are missing local businesses, addresses, places of interest, etc) your area is 'mapped' in OpenStreetMap.
@wills @EricCarroll @Julia
StreetComplete is a great and convenient way to help to make the information more accurate. Used it heavily during my last holiday. And profited from the fact that OSMand and OrganicMaps can also be used where there is no internet connection.