Why not make it a website rather than an app? I think a website would be more attractive for people to try out because it wouldn't require downloading anything onto one's device which seems safer. And also, I'm not sure that I understand the name for the casino because am I right that it has nothing to do with TOR browser and playing there, but rather just refers to Tor as something associated with anonymity? Or is there some connection after all?
What's of course a big risk for such projects aiming at maximum anonymity is that one can be scammed, but perhaps some would give it a try because anonymity is quite attractive.