I use ibispaint on android! I paid like $5 for the full ad-free version a few years ago (one time payment), but using the free version with ads wasn't too bad either. There are only a few brush options but you can work around it by customizing the brushes a lot.
medibang is also cool, it's basically the same as ibispaint in my opinion.
Procreate is definitely good, I've used it on one of my friend's ipads. I have also heard good things about clip studio paint.
Krita is completely free and can be ported to ipad. Haven't used it myself, but it seems good from what one of my friends says about it.
I would not recommend adobe photoshop at all though. It's ridiculously expensive and isn't worth it unless you are a professional artist who will be using it all the time. Personally I don't think it's any better than the free alternatives out there.
I would also recommend getting a stylus or apple pen to use with your device, but just using your finger is fine as long as you take breaks and regularly stretch. the cramps you can get from drawing for 4 hours straight are not fun.