You can start and save your activities, visualize swing paths and speed, track distance, steps, calories and heart rate from your Apple Watch.
To review your workout and swing shot breakdown metrics, you must upgrade to the Pro Edition.
If you have trouble recording your racquet sports activities using your Apple Watch, most likely it is because of connectivity issues. This step-by-step trouble shooting guide should help resolve your problems.
If you like to get a better understanding on how the Apple Watch sensors work, please check out these blog articles.
Learn how to set up and use your Apple Watch for TennisKeeper.