Devans sells the code of old bustabit v1 which had the same design but with Bustabit right now, Devans just took the UI and made it look cleaner.
So did Ethercrash, they took the old bustabit look and made it look cleaner, other sites like bitcrash.us ( not recommended playing there ) has the actual exact same design that was use for Bustabit back in the days.