I'm looking at doing some ATV riding in northern MN and looking at some maps online from the Superior National forest it says "Downloadable map files are geo-referenced for use with smart phone wayfinding apps and some GPS devices."

I tried searching the App store (Apple) for "wayfinding" and "wayfinding MN" but did not find anything useful. Can anyone recommend an app or steer me in the right direction?

Do they mean Google Maps or Waze??

I know lots of people use their smart phone as a GPS or as a mapping tool.
I wouldn't.
Get a stand alone GPS unit, preferably a model that accepts map programs from an SD card.
I use Garmin GPS units exclusively.
Save your phone battery for an emergency call.

Backcountry Navigator Pro.