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. $ Horse Racing Sign-up Bonus & Promo Code () | TwinSpires. TwinSpires Casino offers free slots with bonus rounds and extra rounds. $ [HOST] yet ready to wager real money online? No problem! Find a broad range of free. .