For having a dedicated topo setup I would recommend OSMand. CoMaps/OrganicMaps does contour lines too but you can configure things way more in OSMand and it makes a huge difference. I have both apps so here are screenshots of the same place to compare

Hell half of the front page posts seem to be ads anymore

If you don’t want to use a phone because of privacy concerns there are also stand alone meshtastic devices with blackberry style keyboards too