Privacy Policy
Last updated: October 17, 2026
ZenDepth ("we", "our", or "us") is committed to protecting your privacy. This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use the ZenDepth iOS application.
Please read this policy carefully. If you disagree with its terms, please discontinue use of the application.
1. Information We Collect
We collect the following categories of information:
Account Information
- If you sign in with Apple, we receive a unique Apple user identifier and, optionally, your name and email address. Apple may provide a private relay email address.
- If you sign in with Google, we receive your Google account ID, name, and email address.
- Anonymous users are assigned a random session identifier with no personal data attached.
Training Performance Data
- Personal best breath-hold duration
- Selected training discipline (e.g. Freediving, Spearfishing)
- Session completion records, hold durations, contraction timestamps
- Training phase and session progress
Usage Data
- Anonymous in-app events (e.g. session started, phase completed) used for aggregate analytics
- Crash reports and diagnostic information via Apple's built-in crash reporting
Health Data (optional — Apple Watch & Apple Health)
If you turn on Apple Watch biometrics and grant permission, ZenDepth reads your heart rate through Apple HealthKit during breath-hold sessions. This feature is entirely optional; the app works fully without it.
- What we use it for: only to show live readings during your hold and your post-hold analysis (for example, how your heart rate changed during the hold).
- Where it is stored: on your device and, linked to your account, in our database (Supabase) so it is available across your devices.
- What we never do: we never sell health data, never use it for advertising or marketing, never send it to analytics providers, and never share it with third parties.
- We do not save workouts or other data to Apple Health. (Apple Watch may keep its own heart-rate readings from the session, as it does for any workout app.)
- Your control: you can turn biometrics off in the app at any time, and revoke ZenDepth's access in the iPhone Settings app under Health → Data Access & Devices → ZenDepth. Deleting your account deletes your stored health data.
We do not collect location data.
2. How We Use Your Information
- To provide, personalise, and improve the ZenDepth training experience
- To sync your training data across your devices
- To restore your progress if you reinstall the app
- To process subscription purchases through Apple's App Store (Apple handles all billing; we do not receive payment card data)
- To send you important service notifications (e.g. subscription renewal reminders — Apple handles these)
- To analyse aggregate usage patterns and improve the app (health data is never used for this)
- To show live heart-rate readings and post-hold analysis, if you enable Apple Watch biometrics
3. Data Storage and Security
Your data is stored in Supabase, a managed database platform hosted on AWS in the United States. Supabase applies row-level security — your data is only accessible to your authenticated account.
We use industry-standard encryption in transit (TLS) and at rest. Your Apple or Google credentials are never stored by us — authentication tokens are managed by the respective platform SDKs.
4. Third-Party Services
We use the following third-party services:
- Apple Sign In — Apple Privacy Policy
- Google Sign In — Google Privacy Policy
- Supabase (database and authentication) — Supabase Privacy Policy
- Mixpanel (in-app usage analytics, e.g. "session started") — Mixpanel Privacy Policy. No health data is ever sent to Mixpanel.
- Apple App Store / StoreKit — Subscription billing is processed entirely by Apple
5. Data Sharing
We do not sell, trade, or otherwise transfer your personal information to outside parties. We do not share your personal data with advertisers. Health data obtained through Apple HealthKit is never shared with any third party.
We may share aggregate, de-identified usage statistics (e.g. "60% of users complete Phase 1") publicly. This data cannot be used to identify you.
We may disclose your information if required by law or in response to valid legal processes.
6. Data Retention
We retain your training data, including any health data from Apple Watch biometrics, for as long as your account is active. If you delete your account or request data deletion, we will remove your personal data, including health data, within 30 days.
7. Your Rights
You have the right to:
- Access the personal data we hold about you
- Request correction of inaccurate data
- Request deletion of your data ("right to be forgotten")
- Object to or restrict processing of your data
- Data portability — receive your data in a structured, machine-readable format
To exercise any of these rights, please contact us at the email address below. We will respond within 30 days.
8. Children's Privacy
ZenDepth is not directed at children under the age of 13. We do not knowingly collect personal information from children under 13. If you believe a child under 13 has provided us with personal information, please contact us immediately.
9. Changes to This Policy
We may update this Privacy Policy from time to time. When we do, we will revise the "Last updated" date at the top of this page. We encourage you to review this policy periodically.
Continued use of the app after changes are posted constitutes your acceptance of the updated policy.
10. Contact Us
If you have questions, concerns, or requests regarding this Privacy Policy or your personal data, please contact us at: