Gps navigation app

Been using my macbook pro for a year now and love it. Just bought my wife a macbook air. Finally getting rid of her win doze laptop.
I need a gps navigation app for her air. She used MS streets & trips for navigating while I'm driving the motorhome and needs something comparable that will work on the air.
Anybody know what's available and have actually used it?
I guess we could use google maps while driving but there are areas that have no cell signal.

Your Mac doesn't have a GPS chip (no notebook that I know of has one). You'll need to use a device with a GPS chip (smartphone or tablet) and maybe a data connection (there are a few offline mapping solutions available).