Tim Cook talks incessantly about health being Apple's greatest legacy. They put EKG in the watch. The Muse headband has been out for a long time with fairly good EEG sensing and helps with meditation (I've used it—it works well). I could see Apple including EEG sensing both for meditative practice but also other applications. There are biofeedback devices that use EEG that allow you to play "games" where you control a balloon for example with changing your concentration. Apple wouldn't be first to market, but they weren't with EKG either. Could make a lot of interesting apps that use EEG either for gaming or mental health or both.