Gaia. and followed by avenza, back country navigator, my trails, alpine maps and a slew of others. Try several of them for free from google and/or itunes and you can upgrade the ones you like for 5 to 20 bucks.
I also went with a non connected tablet that does not have gps when no wifi. I have a garmibn glo that I connect to through bluetooth. works for me and I favor gaia (upgraded). YMMV!