The short version: CalmTide computes everything on your device. There is no account, no analytics, and no server that receives your health data. Nothing about your body, sleep, workouts, or stress ever leaves your iPhone.
Last updated: 07/11/2026
What CalmTide reads
With your explicit permission, CalmTide reads data from Apple Health to compute your scores. This may include: workouts and heart rate, heart-rate variability, resting and walking heart rate, sleep analysis, mindful sessions, active energy and exercise time, and — only if you enable the relevant features — respiratory rate, blood oxygen (SpO₂), VO₂ max, time in daylight, Apple stand time (time on your feet), environmental audio exposure, and body mass.
CalmTide reads this data to calculate your HPA Balance Score, daily cortisol status, and trends. All processing happens on your device. The personalized benchmarks and the data-confidence indicator added in version 1.3, and the morning-light coaching, circadian anchor score, and life-event annotations added in version 1.4, are likewise computed on your device, from your own Health data and general published reference ranges — nothing about them is sent anywhere. Life events you pin to your trend are stored only on your device.
What CalmTide writes
One thing, added in version 1.4: when you complete an in-app breathwork or resonance-breathing session, CalmTide saves it to Apple Health as a Mindful Session (Mindful Minutes) — with your explicit one-time permission — so your practice appears in the Health app and counts toward CalmTide's mindfulness metrics. This write goes to your own on-device Health store; it is not data collection by us, and nothing about it is transmitted anywhere. You can decline or later revoke the permission in Apple Health and keep using breathwork normally. Everything else remains read-only.
What CalmTide does not do
- No account. You don't sign up, sign in, or give us an email to use the app.
- No analytics or tracking. We don't use third-party analytics SDKs or advertising identifiers.
- No health data uploads. Your Apple Health data and the scores derived from it stay on your device.
- No selling of data. We have never sold user data and never will.
The SolGlow connection
If you also install SolGlow, the two apps can share a small amount of data through a secure App Group container on your device — a shared file readable only by these two apps. This is device-local; nothing is transmitted over the internet.
SolGlow writes summary values such as morning-sun minutes, a Cortisol Awakening Response score, weekly sun average and streak, and your UV and vitamin D estimate. CalmTide writes back a small summary: weekly HPA balance score, baseline trend, weekly MET-minutes, and hard-session count. No raw health data, identifiers, or credentials cross this boundary — only the summary fields above. Removing either app clears the data it wrote.
Purchases
CalmTide Pro is sold through Apple's App Store using StoreKit. Apple processes the transaction; we receive only the entitlement status needed to unlock Pro features. We do not see your payment details.
Notifications
If you opt in, notifications (a morning check-in timed to your usual wake time, an evening heads-up before a predicted high-cortisol day, a wind-down cue after a late hard session, a post-workout nudge, a weekly summary, and a recovery alert) are scheduled locally on your device. Their timing and content are computed on-device and are not sent to any server.
Data control & deletion
You control Health permissions any time in Apple Health → Apps and Services → CalmTide. Deleting CalmTide removes all of its local data, including cached snapshots and the values CalmTide wrote to the shared SolGlow container. Data stored in Apple Health is owned by Health and remains there unless you remove it in the Health app.
Children
CalmTide is not directed to children under 13 and does not knowingly collect data from them.
Medical disclaimer
CalmTide provides wellness estimates based on published exercise-physiology research. It does not measure cortisol directly, is not a medical device, and should not be used to diagnose, treat, or make decisions about any medical condition. The HPA Balance Score, daily cortisol status, and baseline-cortisol trend are model-based estimates and may be inaccurate. Always consult a qualified healthcare professional about stress, sleep, exercise, or any health concern. Your use of CalmTide is also governed by our Terms of Service, including its health, warranty, and liability disclaimers.
Changes to this policy
If this policy changes, we'll update the date above and, for material changes, note them in the app or on this page.
Contact
Questions about privacy? Email support@twisteddatastudios.com.