K Cast is an app that enables you to securely communicate pitches to your catcher using only hardware you likely already have—your phone and AirPods. No need to buy expensive hardware or set up confusing electronics. Give your catcher one AirPod that is already paired to your phone. We highly recommended you put the phone in transparency mode to let outside sound in. You can then give your pitcher an Apple Watch(worn on the glove hand under a black wrist band) with the Apple Watch K Cast app…