隐私政策 / Privacy Policy

Privacy Policy in English

Scope

This policy explains how the Huanxi iPhone and Apple Watch apps handle data. Huanxi supports everyday observation of personal rhythms; it does not provide diagnosis, treatment, validated psychological stress measurement or emergency alerts. Health access and notifications are optional. No account is required.

Health data we read

Only after you request a connection and choose permissions in Apple's Health authorization interface, Huanxi requests read access to heart rate variability (HRV, SDNN), resting heart rate and heart rate. Readings include values, measurement times and identifiers used to distinguish records. The app does not request sleep, workout, location, contacts or clinical-record access, and does not add, modify or delete Apple Health records.

HRV and resting heart rate queries cover the previous 28 local calendar days and today. Heart rate is limited to up to 200 records from the last 24 hours. Readings are processed on-device for display, trends and comparison with a personal HRV reference. Except for the limited notification receipts described below, the app does not build its own history of health values. It does not upload readings to the developer or third-party servers. Apple Watch queries its own local records, so the phone and Watch may show different data.

Your journal

Feelings, text, context tags, entry times and local entry identifiers that you choose to save are stored in the iPhone app's sandbox for display and deletion. Journal entries do not affect HRV comparisons, are not written to Apple Health and are not uploaded or synced to another device by Huanxi.

Entries remain until you individually delete and confirm them in the journal, or remove the local app data. This version has no in-app import/export, cross-device sync or journal recovery service. Uninstalling loses local entries; do not use the app as your only archive of important information.

Notifications and necessary local records

Only Apple Watch attempts local status reminders, after you opt in and allow system notifications, based on new local HRV readings and your personal reference. The iPhone does not produce status reminders. A reminder includes an unvalidated stress estimate, the actual HRV value in milliseconds and measurement time from that same reading, plus your selected original animal character as a visual cue. Lower HRV relative to your reference maps to a higher estimate, similar HRV to usual and higher HRV to lower. This rule has not been validated for stress prediction; it is not a measurement of psychological stress or a medical diagnosis. Reminders may be visible in the Watch notification interface. Manage system previews and display settings according to your privacy needs.

Pending and most recently accepted notification receipts retain the original HRV value, sample identifier, measurement and submission times, comparison category and selected animal.These bounded receipts keep a notification tied to its original measurement after interruptions, without substituting a later reading or creating a history of health values. Legacy receipts with no value do not receive an invented value. A legacy receipt without an animal uses the default cat. Changing the animal affects future appearance, not the original measurement in an existing receipt.

To remember choices, prevent duplicates and enforce reminder intervals, local files also hold notification preferences, the initial opt-in decision, sample deduplication identifiers, measurement and processing times, and comparison categories. Operational diagnostics contain only necessary operation times, outcomes and error codes, not health values, sample counts or comparison categories. None of these records is sent to the developer or third parties or used for advertising or analytics. Acceptance by the notification system does not prove that you saw a reminder.

You can turn off reminders in Huanxi's notification settings on the Watch, or manage permissions in system settings. Turning reminders off stops future app status reminders and clears pending reminders; it does not automatically erase all local preferences, accepted receipts or Apple Health data. You can clear already displayed notifications in the system interface.

Storage, security and backups

Journal files use complete system file protection; notification records use system file protection after first unlock. Both are kept in an app-specific directory that the app marks as excluded from system backups. Some access-flow or interface preferences use system preference storage. This statement does not mean that the entire device or all system data is excluded from backups.

Huanxi has no developer-operated cloud backup, server storage or data recovery. Apple Health storage, its iCloud sync and device backups depend on Apple services and your settings; Huanxi does not change those settings. Do not assume that deleted local entries can be recovered from a system backup.

If an app file cannot be read, Huanxi preserves it and stops overwriting it, rather than replacing an existing journal or notification settings with an empty file. No technical measure can guarantee against data loss after device loss, damage or system failure.

Data transfer and third parties

This version has no app-owned network client, account server, ads, analytics SDK, cross-app tracking or third-party data-sharing feature. The developer cannot access your health readings or journal through Huanxi and does not sell them.

Apple Health, system notifications, the App Store and TestFlight are Apple services governed by Apple's terms and privacy policies. If you choose to leave the app to visit a support page or contact the developer, the website, email provider or system service may process information. Huanxi does not automatically attach health readings or journal entries.

These support and privacy pages are hosted on GitHub Pages, with network services provided by Cloudflare. Those providers may process IP addresses, browser information and necessary access logs. These pages do not embed analytics scripts, ads or third-party fonts; other code4fun.me pages may have different settings. Support emails you voluntarily send, and their contents, are processed by the developer and email provider only to respond and troubleshoot. Do not send raw health data or your complete journal.

Permissions and deletion

You may use the journal and breathing guidance without connecting Apple Health. In the Health app, open your profile, then Apps and Services and Huanxi to manage read permissions; menu names may vary by OS version. Phone and Watch health access must be checked separately. Revoking access does not delete existing Apple Health records; you manage those in Apple Health.

For privacy reasons, the app cannot reliably distinguish denied read access from having no readable records. Completing the authorization flow does not prove every read permission was granted. Huanxi does not fabricate missing readings or states.

You can delete journal entries individually, turn off Watch reminders, or uninstall the app on the relevant device to remove its local app data. Since the developer holds no copy of your health data or journal, the developer cannot remotely recover, export or change it for you.

Children and health use

The app is not designed specifically for children and makes no claim to provide medical services or medical certification. Its HRV comparison rules have not been clinically validated or validated for stress prediction. Consult a doctor if symptoms persist or before making medical decisions. Stop the breathing exercise if you feel unwell.

Policy changes

If data practices change, we will update this policy and explain changes or request permissions where needed. This policy took effect on November 1, 2026 and was updated on November 2, 2026.

Contact

Developer: Zhishan Zhang. For support or privacy questions, email apple@code4fun.me or read the English support page. Do not send raw health records, complete journal entries, passwords or verification codes. The developer has no copy of your local app data.