Not MTG, but Eternal is a great digital card game very closely based on magic. You should check it out. I've played for a few years now.

We're getting a new set in January, so things will be very fresh for everyone when it drops.

The game is very free to play friendly. This coupled with working very well on mobile makes it my go to game. I only spend Google play money on it that I get from Google surveys and at this point, I can craft anything I want.

The draft format let's you keep your cards and earn gold by winning. It's very lucrative if you're good.