Privacy Policy

Chang Dao does not collect personal information, usage analytics, advertising identifiers, precise location, contacts, photos, or browsing history.

The app does not require an account and does not include advertising or third-party analytics SDKs.

Bookmarks, reading progress, appearance and voice preferences, reminder settings where available, and cached purchase status are stored locally by the app. Rockhammer Labs cannot access this information.

If device backup or transfer is enabled, iOS or Android may back up and restore eligible reading preferences under your Apple or Google account settings. On Android, the cached Full Access entitlement is explicitly excluded from backup and is rechecked with Google Play. Deleting the app may remove local information according to your device, backup, and account settings.

After its first launch, Chang Dao downloads an approximately 175 MB offline voice model from Rockhammer Labs storage delivered by Cloudflare. The download may continue or resume later if the connection is interrupted. Cloudflare receives ordinary network information needed to deliver the files, such as your IP address, request time, and basic connection details.

Model-download requests do not include Tao Te Ching text, listening activity, generated audio, purchase status, account information, or advertising identifiers. The installed model is excluded from device backups and is removed when you uninstall the app.

Tao Te Ching text and reflections are read using speech technology that runs on the device. Chang Dao does not upload reading text or generated audio to a Rockhammer Labs server.

The optional Full Access purchase is processed by Apple through StoreKit on iPhone and iPad, or by Google Play Billing on Android. Rockhammer Labs receives only the purchase entitlement information that the applicable store makes available to the app. We do not receive your payment card details.

Apple or Google processes purchase and account information under its own policies and your store account settings.

On versions that offer a daily reading reminder, Chang Dao asks the operating system for notification permission and schedules the reminder locally. You can disable notifications at any time in Chang Dao or your device settings.

Chang Dao is a general-audience reading app. Because the app does not collect personal information, it does not knowingly collect information from children.

We may update this policy if Chang Dao changes. The date on this page identifies the latest version.