Privacy
Updated 14 October 2026. Covers Mahjong Moonwindow on iOS and Android.
Mahjong Moonwindow is made by The Next Beacon. There's no account to create and no profile, and the game never asks who you are. Signing in to back up your progress is optional, and adverts in the free game come from Google; both are described below.
Below is every field the game sends. Not categories, the actual fields. The list comes from the code that sends them, so you can check it against the game rather than take it on trust.
The game doesn't ask before sending these statistics, because none of them say who you are: no name, no email, no location, nothing you type. Adverts are different: in Europe, Google's consent form asks you first. That's under Adverts below.
What it sends
The game reports anonymous gameplay events to a server we run. We use them to see which boards people give up on, whether the hint button is doing its job, and where a screen is confusing enough that people leave.
About the device, once per batch
| Field | What it is |
|---|---|
vendor_id | The id your phone gives to apps from the same publisher: Apple's "identifier for vendor" on iPhone and iPad, Android's app id (ANDROID_ID) on Android. It's the same across our games on one device, and it lets us count one player of two of our games as one person. It isn't the advertising identifier, and no other company's apps can see it. On iOS it changes once all our games are deleted; on Android it changes after a factory reset. |
install_id | A random id the game makes up the first time it runs. Ours, stored on your device, and gone if you delete the game. It isn't derived from you or your hardware, and it doesn't follow you to another device. |
platform, os_version | "iOS" or "Android", and the system version, so a bug can be tied to the systems it happens on. |
model_class | Just "phone" or "tablet", worked out from the screen size. A model name is close to a fingerprint and all we need is which of the two. |
locale, tz_offset | Your language region, and how many minutes you are from UTC. More on these below. |
app.version, app.build | Which release you're on, so a bug report can be tied to the build it happened in. |
About the game, per event
Every event is a game fact. Nothing you type is in any of them, and there is no field a sentence of yours could fit into.
| Event | What it carries |
|---|---|
app_open | Whether the game started fresh or came back from the background. |
screen_view | Which screen opened, as an internal name like "home" or "settings". |
ui_tap | Which screen you were on and which control you tapped, as internal names like "hint" or "start_run". Never the words on the button, which change with your language. |
run_start | Which mode, how many tiles the board has, and for the marathon, which way its board moves. |
run_end | Which mode, how it ended (cleared or left), how long it took, and how many moves, hints, shuffles and undos it took. |
thousand_flow_chosen | Which way you set the marathon board to move, and whether you changed it. |
board_zoom_changed | The zoom you settled on, and whether you pinched the board or used the setting. |
reader_size_chosen | Which text size you picked. |
cosmetic_chosen | Which theme or tile set you put on, and whether you own it. |
error | Something broke inside the game: the kind of error, where in our code it happened, and the error message the game itself produced. Never anything you typed. |
Two things worth naming
Language and timezone are regional signals. They narrow you down to a region, and we'd rather say so than let you find it in the table and wonder why we didn't. They are not location under either store's definition, and the game never asks for or receives your location.
Our hosting sees your IP address, as every network in between does. We don't collect it, store it, or put it in any of the data above — which is a claim you can check against the field list. What we can't honestly claim is that no computer between you and us ever sees it, because that's how the internet works.
If you send feedback
There's a box in Settings for telling us something is wrong. That one is different: it's free text, and it goes to us as you wrote it, along with which version of the game you're on. Please don't put anything in it you'd mind us reading. It doesn't go through the anonymous statistics described above, and it isn't linked to them.
Buying things
Some themes and tile sets are paid. Apple or Google takes the payment and tells the game whether you own the item. We never see your card details or your billing address, and we don't receive a name or an email address from the transaction.
Children
The game isn't directed at children under 13, and we don't knowingly collect anything from them. There's nothing in it that asks a player who they are.
Keeping it, and deleting it
Events are kept for up to 24 months and then dropped. Deleting the game stops collection immediately.
To have the statistics from your installation deleted, open Settings, find the installation ID under Backup, and send it to info@thenextbeacon.com. That id is the only handle we have — there's no account to look you up by — so we can't find your records without it. We'll delete them within 30 days.
If you've lost the id because the game is already gone from your device, tell us anyway and we'll explain what else might narrow it down. We'd rather say that plainly than promise a lookup we can't do.
Backing up your progress
The game backs up your progress to a server we run, keyed by a random id it makes up on your device. If you choose to sign in from Settings, with Apple on iPhone and iPad or with Google on Android, Apple or Google gives the game an account number that is specific to this game, and we store it next to your backup so you can restore it on a new device. We don't ask for or keep your name or email address. Signing in is optional; the game plays the same without it.
Adverts
The free game shows adverts from Google AdMob: a short advert between some boards, and a video you can choose to watch for more energy. Buying Remove Ads switches all of them off, and from then on the game never asks Google for an advert again.
When an advert is requested, Google receives what any ad network does: your IP address, the device type and system version, and on Android the device's advertising ID, which you can reset or delete in Android's settings. On iOS the game never asks to track you, so Google does not get the iPhone's advertising identifier. None of the gameplay fields listed above are sent to Google.
In the EEA, the UK and Switzerland, Google's consent form asks you first, and you can say no; the adverts are then not personalised. You can change that answer at any time from Settings, under Privacy choices. Google's own use of this data is described in How Google uses information from sites or apps that use its services.
Nothing is sold
We don't sell any of this, and we don't share the gameplay data above with advertisers.
Asking us
Write to info@thenextbeacon.com. If a change here ever matters, this page will say so at the top and the game will ask again.