Yes the OnX app has awesome features for waypoints, including a newer feature that allows you to share waypoints with others via text or email which is very useful. I also like being able to mark and distinguish my waypoints with icons for elk, deer, camp, trailhead, etc.
I download my needed maps to the phone previous to my hunt & then run the phone on airplane mode which lasts a couple days. I also have a small Goal Zero charger that can provide 3 charges to my phone for a longer hunt.