It's funny you mentioned the Road Trippers app. I just downloaded it yesterday after reading an article about it. I ended up uninstalling it pretty quickly as it didn't let me do anything without paying for it. I don't mind paying for software. That's what I do for a living. But I would like to try it out before I buy. I mostly use Google Maps for route, but also RV the RV Parky and RV Life apps are handy. My daughter likes the Waze app, but I just don't like the UI. My two favorites on the computer are RV Trip Wizard and the Good Sam Trip Planner.
https://www.rvtripwizard.com/
https://www.goodsam.com/trip-planner/