Besideswhat you mentioned, the App I use the most with RoadAbode is Google Maps. Not just for GPS, but I can ask "OK Google, wheres the nearest WalMart" Or Ask OK Google show me Grocery Stores" and I can find stuff pretty quick. Past that I enjoy reading books on my Note 2 - and your Note 4 I think is even bigger?
I use a reader called Moon Reader. You can even hook it up to some free library of books.
I use Pandora to listen to online music radio while driving - have tried others and keep going back. Interface is easy.
Glympse is cool - some don't like it though. It allows you to text or email someone your location and they can watch on a map (if they are on a smartphone or computer) your ETA to a location - otr too them. Great when I'm meeting someone so they know when I'll be at the restaurant or whatever.
And all these I use the free versions - except Moon Reader - I bought that when it was on sale for the connect to librarys feature.
Just for Fun - Google Sky to locate Planets, stars and other night objects.
Good Luck - enjoy the new toy!