Privacy Policy

This Privacy Policy explains what information the Hong Kong Mahjong app ("the App," "we," "us") collects, how it is used, and the choices you have. Hong Kong Mahjong is a single-player game — you play against computer (AI) opponents only. There is no multiplayer, no chat, and we never connect you to other real players.

Summary

• You can play the entire game without an account and without giving us any personal information. In that mode everything stays on your device.
• If you sign in (with Google or Apple) we store a minimal account record so your profile, stats, and purchases follow you across devices and so you can appear on the leaderboard.
• We do not sell your data, show third-party ads, or track you across other apps and websites.

Information we collect

1. Information stored only on your device

Whether or not you sign in, the following is kept in local storage on your device and is not sent to us unless you sign in:

• Your display name and chosen avatar
• Gameplay statistics (hands played/won, faan, self-draws, deal-ins, training accuracy, achievements, and recent hand history)
• Your selected tile theme and app settings
• Records of purchases/entitlements (which tools you own; Plus status)

2. Information collected if you create an account

When you sign in with Google or Apple, we receive and store:

• A unique account identifier
• Your display name and (if provided) avatar/photo reference
• The email address associated with the sign-in (used only to identify your account; we do not email you marketing)

We use a third-party authentication provider (Google Firebase Authentication) to handle sign-in. We never receive or store your Google or Apple password.

3. Leaderboard information

If you sign in, your display name, avatar, and game score may be stored in our cloud database (Google Firestore) and shown to other players on the public leaderboard. If you do not want to appear on the leaderboard, play without signing in, or sign out.

4. Purchase information

In-app purchases and the Plus subscription are processed by the Apple App Store, and validated through our payments provider (RevenueCat). We receive a record of what you purchased and your entitlement status. We do not receive or store your credit-card or full payment details — those are handled entirely by Apple and RevenueCat.

How we use information

• To save and sync your profile, stats, and purchases
• To display the leaderboard
• To unlock the features and cosmetics you have purchased
• To operate, maintain, and improve the App
• To detect and prevent fraud or abuse

We do not use your information for advertising or sell it to third parties.

Third-party services

The App relies on these processors, each under their own privacy policy:

• Google Firebase (Authentication + Firestore database) — account and leaderboard data
• Apple — Sign in with Apple and App Store purchases
• Google — Sign in with Google (authentication only)
• RevenueCat — purchase/subscription validation

Data retention and deletion

Local data is removed when you uninstall the App or clear its storage. If you have an account and want your cloud data (account record, stats, leaderboard entry) deleted, use the Delete account option in the App's account screen, or contact us at the email below — we will delete it within 30 days.

Children's privacy

The App is not directed to children under 13 (or the minimum age required in your country). We do not knowingly collect personal information from children. The App contains no real-money gambling — in-game scoring uses points with no cash value.

Your choices

• Play without signing in to keep all data on-device.
• Sign out at any time from the account screen.
• Delete your account and data at any time from the account screen, or via the contact email.
• Manage or cancel the Plus subscription through your App Store account settings.

Changes to this policy

We may update this policy from time to time. Material changes will be noted in the App and by updating the "Last updated" date above.

Contact

Questions or data requests: andrew@revenuearc.com