Is there a good app for long distance secondary roads?

I have been using Maps.me

Great zoomed out view of primary and secondary roads throughout the US and Australia. Have not used in other countries yet.

As you zoom into a specific area it will prompt you to download a more detailed map of that area. Minor downside, maybe. May require some preplanning or WiFi or Data.
But the detailed maps don’t take up much space. And you can delete unused maps easily.

Have not tried to use offroad.

Simple to use turn by turn navigation feature.