I use BackCountry Navigator PRO on my Android phone. Like other similar apps, it allows me to download and store various maps and then functions like a handheld GPS unit, set waypoints, record tracks, plot routes, find distances and elevation, etc. I have an older Garmin eTrex, but I rarely use or even take it. The touchscreen on the phone is just so much better for navigation and has a bigger screen. I do still take paper maps and use them for planning before I start out or to refer to while driving to a location.
I have all of the older USFS topo maps for the Shawnee as well as some other National Forests. Those appear the same as the old school topo maps that USGS and USFS used to produce as paper quadrangle maps. Unfortunately they replaced these older legacy topo maps with the newer National Map and that is what I get now for any new downloads of FS maps, but as long as I keep the map tile files I have stored, I can continue to use what I have downloaded. I've transferred them from phone to phone and have them backed up on my computer. I like the look of those older classic USFS topo maps and wish I had downloaded more for other places I would like to go someday. Perhaps there are other users of this app that have some other USFS maps downloaded that would share the files if I knew how to contact them.