I use a phone app called "US Topo Maps Pro" that allows you to preload map areas for later offline use, a feature I find really useful. I know theres a way to drop map pins and enter waypoints but I haven't yet tried it. My favorite thing is all the options for map imagery- there's the standard USGS topo, older scans of paper maps, forest service maps, nautical charts, etc. The layer I use most is called "Scanned Topo Maps USA Dynamic" which gives the greatest detail for dirt roads and trails. My Delorme's NJ Gazeteer was starting to fall apart, and a paper map doesn't help you if you're totally lost with no landmarks by which to orient yourself. The app was well worth the $10 price, just make sure you preload the map data while you still have cell service. The GPS will continue to designate your location, but without mobile data you won't see any map imagery otherwise.
You might check out my "1999 in the Pines" map. It contains the final version of these legacy USGS topo maps and the quality is higher than any of the versions I've seen elsewhere. https://boydsmaps.com/1999-in-the-pines/
My version is on the left, the ArcGIS version used in many apps (including here in NJPB maps) is on the right.