Privacy policy
Mom Jong is a small app. We collect as little as we can to let you play with friends. This page says what that is.
The short version
- Learning, practicing and playing the computer happen on your phone. We receive nothing.
- Online play uses an anonymous guest account. No email, no password.
- No ads, no tracking, no selling or sharing your information.
- You can delete your account, and everything we hold about it, from inside the app.
Playing on your own
Practice, tutorials and games against the computer happen on your phone. Your scores, tile style, saved tables and the cards you add are stored on your device and are not sent to us.
Playing online with friends
If you use “Play with friends online”, we create a guest account for you. For that we store:
- A random account ID and the sign-in token your phone keeps.
- Your display name and emblem, and your chosen tile style. Other players at your table can see these. Please don’t use your real name if you’d rather not.
- Tables and seats you create or join, with invite codes.
- The card you upload to a table. It is encrypted on our server and used only to check that everyone at the table has the same card and to run the game. It is never sent back to any device, including yours, and it is never shown to other players.
- Game activity needed to run a game, such as moves while a game is in progress.
- Basic usage events (for example “joined a table” or “finished a game”) tied to your account ID, so we can tell whether the app works. We do not use advertising or tracking SDKs and we do not sell data.
- A push-notification token, only if you allow notifications, so we can tell you when a friend deals a hand.
- Your IP address, briefly, to limit abuse. It is not stored with your profile.
Our website
This website sets no cookies and has no analytics or advertising trackers. Our hosting provider keeps ordinary server logs (such as IP address, time and page requested) for security and reliability.
Who sees it
Only the other players at a table you’re in, and only your display name, emblem, tile style and whether you’re online. We don’t share your information with advertisers or data brokers.
A few companies handle data on our behalf, and only to run the app: Fly.io hosts our servers, and if you turn notifications on, Apple (for iPhone) or Google (for Android) deliver them using your notification token. They are bound by their own privacy policies and don’t get to use your data for their own purposes through us.
How we protect it
Everything between the app and our servers travels over an encrypted connection. Uploaded cards are encrypted on our server with a key kept separate from the data, and access to our systems is limited to the people who run the app.
Keeping and deleting your data
We keep your account information while your account exists. In the app, open Play with friends online and choose “Delete my account”. That immediately removes your account, your uploaded cards, your seats and your notification token from our server, and removes your account ID from usage events. Encrypted backups are overwritten on their normal rotation, within 30 days. You can also ask us to do it by email — see how to delete your account. Deleting the app removes everything stored on your phone.
Children and age
Playing on your own stays on your phone and collects nothing from us, and anyone can do it. Online play is for people aged 13 and over, or the higher age required by the law where you live. Before you first play online, the app asks how old you are. If you’re under 13, we don’t create an account and nothing is sent to us; the app doesn’t keep the year you enter. We do not knowingly collect personal information from children under 13. If you believe a child has an account, email support@checkmatelabs.app and we will delete it promptly. We do not sell or share anyone’s personal information, we show no ads, and we use no advertising identifiers.
Your rights and our legal basis
If you’re in the EU, UK or a similar region, we use your information to provide the game you asked to play (contract), to keep it secure and working (legitimate interests), and to send notifications only if you allow them (consent, which you can withdraw in your phone’s settings). You can ask to access, correct, delete, export or object to our use of your information, and you can complain to your local data protection authority. California residents have the rights to know, delete and correct, and not to be treated differently for using them; we don’t sell or share personal information. Because we don’t track you across apps or sites, there is nothing to opt out of, and we treat any “Do Not Track” or global privacy signal the same way. Email support@checkmatelabs.app and we’ll reply within 30 days.
Moving data
Our servers are in the United States, so information is processed there. The controller is Checkmate Labs, LLC, reachable at support@checkmatelabs.app.
Changes and contact
If this policy changes, we’ll update the date above and post the new version on this page. Questions: support@checkmatelabs.app.