Privacy Policy

ZhouYi Master AI is a Yijing (I Ching) reflection app for iPhone. We collect as little as we can and we don't sell anything.

• No account, no sign-up, no email required to use the app.
• No advertising SDKs, no analytics SDKs, no third-party trackers in the app.
• Your readings, journal, conversations, and profile stay on your device.
• When you talk with Yi Master, your message and the context it needs are sent to our server only to write the reply.

ZhouYi Master AI ("we", "us", "the app") is an independent product built and operated by Max Li Bin (Singapore). Contact: me@maxlibin.com.

The following never leaves your iPhone:

• Your coin casts, readings, and journal.
• Your saved conversations with Yi Master.
• Your profile, including birth date and gender, which are never sent anywhere.
• Motion sensor readings used to toss the coins, which are processed on the device and not stored.

These are stored using Apple's standard on-device storage. They are included in your iCloud device backup only if you have iCloud backup enabled in iOS. Deleting the app removes them.

When you send a message to Yi Master, the app sends the following to our backend (a Cloudflare Worker we operate) so it can write a reply:

• Your message and the recent turns of that conversation.
• A reading you chose to attach, if any.
• The profile fields you filled in: name, situation, goals, and concerns.

Our backend passes this to DeepSeek's API to generate the reply and streams it back to you. We do not store your messages on our server. DeepSeek processes the request under its own privacy policy and may process it outside your country, including in the People's Republic of China.

If our server cannot be reached and your iPhone supports Apple Intelligence, the reply is written by Apple's on-device model instead, and nothing is sent.

The app creates a random identifier for this installation and keeps it in your iPhone's Keychain. Our server uses it to keep your Yi Master balance: how many replies you have used, their token counts and cost, and which subscription, if any, this installation is linked to. It is not linked to your name, email, or Apple Account.

Payments are handled entirely by Apple. When you subscribe or restore purchases, the app sends Apple's signed transaction record (transaction identifiers, product, renewal date, and whether it is a test purchase) to our server, which checks Apple's signature and refills your monthly replies. We never see your payment details, full name, or Apple Account.

Your IP address is used to enforce a daily request limit. It is kept only in a counter that expires at the end of the day (UTC).

Our server keeps short-lived operational logs (for example request events and error messages) so we can keep the service running. These logs do not contain your messages and are not used for advertising or sold to anyone.

We do not embed advertising SDKs, analytics SDKs, or third-party trackers in the app. We do not use the IDFA. We do not build a profile of you.

ZhouYi Master AI is not directed at children under 13, and we do not knowingly collect personal information from them. If you believe a child has sent personal information through the app, email me@maxlibin.com and we will delete it.

On-device data lives until you delete it in the app or delete the app. Your credit balance and reply records are kept on our server while the service runs, so your balance and subscription keep working. Email us to request their deletion.

Depending on where you live, you may have the right to access, correct, delete, or restrict processing of your personal data, and to lodge a complaint with a data protection authority. Email me@maxlibin.com and we'll respond within a reasonable time.

We may update this Privacy Policy from time to time. We'll change the effective date above and, for material changes, surface a notice in the app.

Questions about this policy? me@maxlibin.com