GPS

I use CoPilot for RV on my iPhone 6s Plus. I also have and use Waze and Google Maps.

Try the free ones first then you can update if you like it.
Copilot is a good one to start with.

I use a tablet. Waze in the foreground and Google maps in the background. Sometimes one will catch an issue before another. And I like Google giving options while driving.

Google maps Iphone 6S Plus

I use Google Chrome Maps but I have an android phone. Here is a list of apps for iphone

I use Waze. It works great.