Cook expects an explosion of new apps for the Apple Watch. One of the Apple Watch's great missions will be to harness new technology to help improve users' health. The Apple Watch will of course be able to monitor heart rates, Cook says; but it will be far more sophisticated than that. It is bad for people's health to sit too much; so the watch will gently tap people's wrist every hour to remind them to stand up and go for a walk if they haven't had enough exercise.