Summary
Crescendo 4×4 does not collect, store on servers, transmit, or share any personal data. There are no accounts, no analytics, no tracking, and no ads. The app reads and writes Apple Health data only with your permission, only on your device — we never see it.
Apple Health (HealthKit)
With your explicit permission, Crescendo 4×4 uses HealthKit for exactly two purposes:
- Reading your date of birth (to estimate your maximum heart rate), resting heart rate, and VO₂max — used to personalize your 85–95% training zone and to conservatively time level-ups. Reading is optional: you can enter a max heart rate manually instead.
- Writing your completed workouts to Apple Health, so they appear alongside the rest of your activity. You can switch this off in Settings at any time.
All Health data is processed on your device. It is never uploaded, shared, or used for advertising or analytics — the app has no server to send it to. Health data is also never used in ways you haven't authorized, in line with Apple's HealthKit rules.
You can review or revoke Health access at any time in the Health app under Sharing → Apps & Services → Crescendo 4×4.
Data stored on your device
Your settings and workout history (levels, completed sessions, dates) are stored locally on your device. Deleting the app deletes this data. Workouts you chose to save to Apple Health remain in Health under your control.
What we collect
Nothing. No user accounts, no analytics, advertising, or tracking SDKs, no crash reporting, no server.
Children
Crescendo 4×4 is designed for adults. High-intensity interval prescriptions and adult heart-rate formulas are not appropriate for children; the app requires an age of at least 13 during setup.
Changes to this policy
If the app's data practices ever change (for example, adding opt-in crash reporting), this policy will be updated before the change ships, with the dates above revised.
Contact
Questions about privacy? Send us a message — a real person reads it.