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Yes. Real swing speed requires the motion sensors of a physical Apple Watch; the simulator provides no motion data. The app runs on Apple Watch Series 6 / SE (2nd gen) or later (watchOS 11 – older models like Series 4/5 cannot install it); impact timing at 800 Hz needs Series 8 or later (or Ultra).

We are deliberately honest: racket-head speed is a radius-based estimate (±10–20 %); the radius can be matched to your racket. Wrist speed is ±5–15 %. MyPowerTennis measures the racket, not the ball, and is no substitute for video analysis or professional coaching. The values are excellent for comparing and improving over time.

On Apple Watch Series 8/9/10 and Ultra 1/2 we sample the sensors at 800 Hz to determine the exact contact moment (±1–5 ms), the acceleration time, the follow-through time and a timing index. On older models speed measurement works; only the high-resolution timing is unavailable.

Apple Watch Series 6 / SE (2nd gen) or later with watchOS 11.0+, plus iPhone or iPad running iOS or iPadOS 18.2 or later. The app must be installed on both the Watch and the iPhone.

Forehand, backhand and serve are detected automatically from gyro analysis. On groundstrokes the app also estimates spin tendency (topspin, flat, backspin); for serves it evaluates contact height and pronation angle.

Every session can be shared as CSV (one row per sample) or a print-ready PDF. There is also a full JSON archive of all sessions for backup and transfer.

The Apple Watch can have its own language. It is set on the iPhone in the Watch app: My Watch → General → Language & Region. A per-app language chosen on the iPhone (Settings → Apps → MyPowerTennis → Language) only applies to the iPhone app – the Watch app always follows the Watch's language. After changing it, close and reopen the Watch app once.

Your sessions are stored on the device and – if enabled – synced via your private iCloud (CloudKit) across your Apple devices. There are no own servers and no tracking. See the privacy policy for details.