I bought this a couple months ago (made an account for it) and have been using it to play blackjack semi regularly since. I actually learned to play blackjack just for it. Only recently did I decide to download a dedicated app since this doesn't have surrender, insurance (which I want to practice) and of course card counting (I mean I assume every hand is independant and there isn't an actual "deck" anyway, I never actually tried to keep track to check, but you're never made aware of a shuffle so it would be a weird thing to be add). But since you can't win blackjack without card counting, you'll just be slowly losing money if you can't do it. It's a lot more fun to watch a number slowly go up. Plus I do really enjoy the comforting atmosphere the girls provide, although I mostly stick with Onee-san. So I guess if there was something I would add, it would be the possibility of card counting, but the stress of being expected to do that might run a little contrary to that calm atmosphere, so maybe it's not too bad just being a basic strategy exercise.
Memorable moments include screenshotting rare instances and chip milestones, and of course coming around for the animation now and then. I haven't actually touched the other games much other than trying them out near the beginning and once instance where put my whole bankroll on red and lost. Maybe I'll have a similar adventure with poker with that whole facial expression thing being the thing I'm happy to skip using this app like counting in BJ. <3