Unfortunately we dont have a tool for provably fair . We will start working on it in the next couple of days. As for the maximum bet, there is none.
how can your system be provably fair if the odds on a 2x game is 50%
this means that your game has no house edge i.e. you are making money...some other different way
this is one of the multitude of the scripts very popular past couple of years,if I'm not mistaken
and yeah,nobody would bet on your site untill you get some sort of a bet verifier