DraftKings said Wednesday it has launched its DK Horse betting app in 12 states and anticipates the rollout in additional states by May 6, the date of the Kentucky Derby. DK Horse allows eligible customers access pari-mutuel wagering on horse racing once they have registered and deposited funds into their accounts. The app also gives customers the ability to handicap races, stream video of races and obtain information about future races, DraftKings said.