cat nightrecovery/README.md
NightRecovery
Wake up to a recovery score built from your own overnight trends.
NightRecovery reads HRV, resting heart rate, sleep stages, and respiratory rate from Apple Health and computes a personalized recovery score (0–100) every morning. Think Whoop or Oura, but running entirely on your iPhone with no subscriptions, no account, and no data leaving your device.
Core features
- Recovery Score — weighted composite of HRV, resting HR, sleep, and respiration against your 30-day rolling baseline.
- Signal breakdown — per-metric rows showing raw value vs. baseline delta with individual sub-scores.
- Drivers & explanations — human-readable notes on what moved your score up or down.
- 7-day trend chart — track recovery patterns over the past week.
- Background sync — anchored HealthKit observer queries keep data updated automatically.
- 6 languages — English, Italian, German, French, Spanish, Portuguese.
How scoring works
- HRV (SDNN) — 40% weight
- Resting Heart Rate — 25% weight
- Sleep duration + efficiency — 25% weight
- Respiratory rate — 10% weight
Each signal is z-scored against a 30-day median baseline using robust statistics. Scores are provisional until 14 valid nights, with a minimum of 7 nights before any score appears.
Privacy
- All processing happens on-device. No cloud, no backend, no network calls.
- Read-only HealthKit access. The app never writes to Apple Health.
- No account, no analytics, no trackers, no ads.