Apple Fitness+ is a subscription-based fitness service designed to work with Apple Watch. It offers a wide range of workout classes led by professional trainers, including strength training, yoga, cycling, running, and more. The service integrates seamlessly with your Apple devices, displaying metrics like heart rate and calories burned on your screen during workouts. It also includes personalized recommendations, monthly challenges to help keep users motivated, and meditative cooldowns, all tailored to your fitness goals.