I've been drawing on Sketchbook (the free version) for a little while now on my iPad. I was thinking of getting the paid version since it offered so many nice things, but I also saw Ibis Paint, so I don't know?
Since I've had the iPad for a while, I only really use it for playing MCPE and drawing, and I still get a lot of gift cards, so I have a bunch of credit right now.
Read more: Ibis Paint or Sketchbook?