Starry Mahjong Privacy Policy

Last updated: 5 November 2026 · App version 1.2.7 · 繁體中文

Starry Mahjong ("the app", "we") is a single-player mahjong game. This page explains what the app does with your information. In short: the app never asks who you are. From version 1.2.7 it keeps an anonymous copy of your game progress on our server, and, unless you turn it off, shares anonymous hands and a few details of how you use the app, to help improve the game. We don't sell or share any of it.

What stays on your device

Your game is saved on your phone: stars, marbles, level, shop items, daily missions, settings, statistics, and a log of the hands you played. Deleting the app or using "Reset progress" in Settings removes it from the phone. What the server receives is below.

What we collect

The app never asks for your name, email, location, contacts, photos, microphone or camera. It contains no third-party advertising, analytics or tracking tools, and it doesn't use an advertising ID. When your phone is online, it sends three things:

• A progress copy. The app signs in with an anonymous account (a random id, shown in Settings > Manage data as your Player ID) and keeps a copy of your game progress with it: marbles, stars, level, packs, collected sets, items you own, your equipped theme, your recent marble changes, hands, wins and games played, your rules, difficulty and language choices, the app version and your platform (Android, iOS or web). We use it to check the game's economy, to fix problems you report, and to send you gifts. So that deleting and reinstalling the app keeps the same Player ID on the same device, the app keeps this account's sign-in on the device: on iPhone and iPad in the Keychain, on that device only and never in iCloud; on Android as a sign-in code made by scrambling the device's Android ID one way, so the Android ID itself is never sent or stored. It doesn't follow you to another device.
• Anonymous hands, when "Help improve the game" is on (it is on unless you turn it off; you can turn it off in Settings > Manage data or when the first hand starts). For each hand you finish or leave early: the tiles dealt, the moves, the result and score, your rules and difficulty, the app version and the day it was played. These carry no account id, Player ID or device id; hands from one launch of the app share a random id that changes each time the app starts. Hands in your log from earlier versions that were never sent are shared the same way once you have seen the switch, under a separate random id; hands played while the switch was off are never sent. We use them to tune the computer players and the difficulty levels.
• How you use the app, also only when "Help improve the game" is on. Items marked "with the anonymous hands" travel in those hands and carry no id; the rest are kept with your progress copy, so "Delete my server data" removes them. We use them to see where the game is hard to follow, to fix bugs and to fit the layout to more screens.
  • How long you take to choose each discard and each claim, rounded to a tenth of a second (with the anonymous hands).
  • Whether hints were shown and whether you followed them (with the anonymous hands).
  • If you leave a hand early, the turn you left on (with the anonymous hands); how far you got in the tutorial, or the step you skipped at.
  • How many days you have played, how many sessions, total minutes and rough session lengths, never the times of day.
  • Which shop items you opened or previewed, and how many times.
  • Short error messages from the app, with the file and line, to help us fix bugs; no stack traces or personal content.
  • Your screen size, pixel density, platform and major OS version; no device name, model or browser string.

We don't sell this information, share it with anyone else, or use it for advertising.

Internet use

The game, including its voices and sounds, is fully contained in the app and plays without a connection. The progress copy, hands and usage details are sent when a connection is available, through Google Firebase (Google Cloud, United States), which stores them for us under Firebase's privacy and security terms. Like any internet connection, the server sees your IP address while it answers; we don't store it with your data, though Google may keep it briefly in its own service logs.

Deleting your data

Settings > Manage data > "Delete my server data" removes your progress copy, the usage details kept with it, any unclaimed gifts and the anonymous account from the server, and gives you a new Player ID. Shared hands, including the think times, hints and early exits in them, can't be deleted, because nothing in them links them to you. Turning off "Help improve the game" stops new hands and usage details from being sent, clears the usage details counted on your phone, and removes them from your progress copy the next time it is sent. To ask about your data, email us with your Player ID.

How long we keep it

The progress copy, with the usage details kept with it, is kept, and carries over to later versions of the app, until you delete it (turning the switch off removes the usage details). Anonymous hands, including their think times, hints and early exits, are kept for as long as they help balance the game.

Backups

Settings has a backup feature that saves your progress as a file, or as text you can copy. You choose where it goes, for example your files or a message to yourself. We do not receive it. "Send play data" in Manage data works the same way: it makes a file of your hand log, which we receive only if you choose to email it to us.

Google Play

If you install the app from Google Play, Google handles the download and may collect information under Google's Privacy Policy. We don't receive that information from Google beyond anonymous install statistics shown to developers in Play Console.

App Store

If you install the app from the App Store, Apple handles the download and may collect information under Apple's Privacy Policy. We don't receive that information beyond anonymous statistics shown to developers in App Store Connect.

Simulated gambling

The game uses "stars" as a betting score and "marbles" as an in-game currency. They have no real-world value. They cannot be bought, sold or cashed out in this version, and nothing in the app involves real-money gambling.

Children

The app is not directed to children under 13. The progress copy, usage details and shared hands are anonymous game data and never include a name or contact details. If you believe a child's progress copy should be removed, use "Delete my server data" or email us with the Player ID.

Changes

If a future version collects other data, shows third-party ads or adds purchases, we will update this policy first. The date at the top shows when it last changed.

Contact

Questions: trayerstudio.dev@gmail.com