. TwinSpires Casino offers free slots with bonus rounds and extra rounds. Experience the thrill of online betting with real money sportsbook and online casino games on your mobile with TwinSpires Casino & Sports. The casino offers generous welcome bonuses as well as an array of the top slot games. $ [HOST] yet ready to wager real money online? No problem! Find a broad range of free. $ Horse Racing Sign-up Bonus & Promo Code () | TwinSpires.