I notice that you don't have a tip feature, some sites do have that, other users can give tip to each other (I find it okay if you'll add). More important thing I would like to suggest is to have an additional case which users can bet using 10 bits even can only win from 10 to 50 bits . It is because, I played and for my last chance I got less than 50 bits (specifically 40). If I only have less than 50 in my balance, I can't use it anymore to play unless I'll deposit or wait for the faucet.
Transfer to another user bits, we already develop. About small cases you can wait little and claim bits