Trailforks or Maprika will show your GPS location on a map stored on your phone so it shouldn't burn data, but it won't give you turn-by-turn navigation. I'm guessing you are looking for audio or video prompts? I guess if you have your phone mounted to your bars and know how to read a map, you can easily take turns at intersections of one of those apps depending on where you GPS dot puts you. Anything else with turn-by-turn I would assume would use data on a phone. Sounds like you want to look into a Wahoo/Garmin with mapping.