Privacy Policy

Effective date: 2 July 2026 · Contact: hello@mahjiku.com

We built Mahjiku to score Hong Kong mahjong and help you learn. The app records game points only — it involves no real-world money, wagering, or gambling. We collect as little as possible and never sell your data.

What we collect

Account info (email and name). When you sign in with Google or Apple, we receive your email and display name to create your account and sync your games across devices. That's the only reason.
Game data. The scores, hands, and sessions you record, so we can show your scoreboard and history.
Hand photos — only with your consent. If you leave "Contribute photos to improve recognition" ON (Settings; you can turn it off anytime), a downscaled photo of a winning hand plus the tiles you confirmed are uploaded to help train our on-device tile reader. If you turn it off, nothing leaves your phone.

We do not collect your location, contacts, or precise identifiers, and we use no advertising or third-party tracking SDKs.

How we use it

To run the app (accounts, scoring, live scoreboards), to sync your games, and — only with consent — to improve the accuracy of our tile-recognition model. Nothing else.

How it's stored and shared

Your data is stored with Supabase (our hosting/database provider, acting on our behalf) and encrypted in transit. We do not sell your data or share it with advertisers. We only disclose data if legally required.

Your choices and deletion

Turn photo contribution off anytime in Settings.
Delete your account anytime in Settings → Delete account — this permanently deletes your account, games, and their history from our servers.

Children

The app is not directed to children under 13, and we do not knowingly collect their data.

Changes

We may update this policy; we'll change the effective date above and, for material changes, notify you in-app.

Contact

Questions? Email hello@mahjiku.com.

This page is the public privacy policy linked from the Google Play & App Store listings and from the in-app Privacy screen.