Brainscape Pro appears to run much more smoothly than the free version with the ability to use more than plain text as well as to make card sets secret and to add photos (and I believe audio?) to one's flashcards. It appears to be a pretty well-oiled machine, minus how folks using the free version may get blocked out from Pro users' cards once they edit them, which is frustrating. I would like to see this issue being remedied. Also, the Pro app comes at a very high price point. For this price, I hope that no further issues will arrive as well.

helps me focus on what I'm studying, i like the simplicity

The best thing about Brainscape is how quick it allows you to memorize things! It works with literally every subject