Zero Third-Party Tracking · Zero Data Selling

Privacy Policy — Mahjong Four Walls

Developer: MGC Engineering Studio LLC | Effective Date: November 8, 2026

MGC Engineering Studio LLC ("we", "our", or "us") built Mahjong Four Walls ("the App") for iPhone, iPhone Duo, iPad, and Mac with privacy as a core principle. We do not operate advertising surveillance SDKs, we do not track you across apps or websites, and we do not sell or rent personal information.

1. Information Stored on Your Device & Personal iCloud

Game Progress & Preferences: Your World Tour progress, custom Cantonese Mahjong rule preferences, puzzle history, and cosmetic loadouts are saved locally on your device via Apple UserDefaults and synced across your own Apple devices using your private Apple iCloud Key-Value Store (NSUbiquitousKeyValueStore) and Game Center Saved Games.
We do not have access to your personal iCloud storage or Apple ID credentials.

2. Apple Game Center & Multiplayer

If you choose to sign in to Apple Game Center, Apple provides the App with your public Game Center display alias and scoped player identifier solely to display your seat name at multiplayer tables and submit scores/achievements to Apple Game Center leaderboards.
When playing on local Wi-Fi / Hotspot parlors, the App uses Apple's local network discovery strictly to connect nearby Mahjong tables in your session.
When joining optional cross-network 4-digit private parlor room codes, the App uses an ephemeral WebSocket relay solely to route live turn actions in memory during an active match, with zero personal data storage, logging, or tracking.
Game Center data is governed by Apple's Privacy Policy.

3. In-App Purchases

All optional purchases (such as the one-time Parlor Patron pass) are processed directly and securely by Apple via StoreKit 2. We never receive or store your credit card, billing address, or Apple Pay details.

4. Analytics, Third-Party Ads & Tracking

The App contains no third-party advertising SDKs, no behavioral analytics trackers, and performs zero cross-app tracking (NSPrivacyTracking = false).
Website vs. App: While the iOS and Mac App collects zero data, our public website may measure aggregate visit and tool-usage metrics.

5. Virtual Score Chips Disclaimer

"Parlor Chips" in the App are purely virtual score counters used to tally traditional Cantonese Mahjong Faan hands. They have no monetary value and cannot be purchased, wagered for real money, or exchanged for cash or prizes.

6. Children's Privacy

We do not knowingly collect personal information from children or any other users.

7. Contact Us

If you have any questions about this Privacy Policy or the App, please contact MGC Engineering Studio at: contact@mgcengineeringstudio.com.