Everything looks awesome man. Great design, everything seems fluent.
I've noticed that if I try to bet anything lower than 100 satoshis on 98% return, it says I can't bet because it would return 0 to me. Obviously this makes sense because the profit would be lower than a satoshi, but i don't know if there would be any way to prevent this from even being a possibility or something. I really like that there is already an app lined up for this too. Major kudos for that.
Obviously the help page is blank, but I assume that will be filled in later.
A suggestion I have is to set up a password for your account, rather than using the cookie, you should drop the need for an email address and just do straight up username and password. Many people would probably prefer to not have an email tied to a gambling website.
I would also add more stats if you could. People love stats.
Last thing, is I would prefer to use my own client seed, rather than randomly generating new ones.
All in all, great job dude!