After decades of using paper maps with out of date info sometimes, and no close detail, its become an important tool for me. Used a cheap 15 dollar mount from walmart, not the best but it held my Iphone over some bumpy roads. Now it stays in a bar bag as it was hard to see in the daylight anyway.

Mostly I use this MAPS.ME (MapsWithMe), detailed offline maps of the World for iPhone, iPad, iPod, Android, Amazon Kindle Fire and BlackBerry with a smattering of Google for city navigation. Still carry state maps for a big picture.
If I ever get to take a long trip again the plan is to take an Ipad for its larger screen. Charging happens at campgrounds and such with my aging Mophie pack as standby. Good for about four charges of a phone.

There is a thread on the Katy trail right now with some links to a route from St Charles to the Kirkwood train station. Did that some years ago using a tourist flyer picked up at a hotel lobby. While I made it, I never knew 100% where I was, and took some wrong turns. Would have shaved some miles off with the tech available to me now.

One thing I have done is use the satellite imagery to locate buildings in cities that I am looking for, can't find, but am standing behind, one block over, or even right in front of. Cities are my weakest point of navigation.