PureMaps, Navit, GNOME Maps, Marble, TangoGPS, various OSM web UIs... There's plenty of GNU/Linux apps, some of them providing online and offline turn-by-turn

PureMaps, Navit, GNOME Maps, Marble, TangoGPS, various OSM web UIs... There's plenty of GNU/Linux apps, some of them providing online and offline turn-by-turn navigation, and some of them even already working well on mobile form factors. The software will surely need some time in order to get polished enough to be used by a total newbie out-of-the-box, but it's not like there's no software for that at all.