Sudoku Privacy Policy
Effective date: October 2, 2026
This Privacy Policy explains how Langfang Zilingxing Technology Co., Ltd. ("we", "us") collects, uses, shares and protects information when you use our Sudoku app on iOS and Android outside mainland China. The app appears in app stores under localized names such as "Sudoku Climb: Logic Puzzles", "ナンプレ・数独 - 段位が上がる脳トレ", "스도쿠 클래식: 두뇌 트레이닝", "數獨控", "Sudoku Bậc Thầy", "ซูโดกุ - เกมฝึกสมองผู้ใหญ่" and "Sudoku - Teka-Teki Asah Otak". Users in mainland China are covered by our separate Chinese privacy policy.
This policy is available in several languages. If the versions differ, the English version prevails.
1. Summary
- You can play without registering. We assign an anonymous User ID (shown as "Sudoku ID" on the Me page) to save your progress and rankings.
- The app is free and supported by ads from Google AdMob. Where required by law, we ask for your consent before ads are personalized, and on iOS we ask for permission before your advertising identifier is used for tracking.
- Optional one-time purchases are processed by Apple or Google. We never receive your card or bank details.
- Our servers are located in mainland China.
- We do not sell your personal information.
2. Information we collect
2.1 Information you provide
- Nickname (optional): if you set one, it is shown with your results on leaderboards.
- Puzzles you enter or share: custom puzzles you type in or save, and share codes you create.
- Photos you choose for Photo Solve: when you use Photo Solve, the photo you take or select is uploaded to our server so the puzzle can be recognized. We use it only for this purpose.
- Support messages: what you send us when you contact support.
2.2 Information collected automatically
- User ID: an anonymous identifier assigned by our server the first time you use the app after accepting this policy.
- Game data: progress, rank tier, stage and Daily Challenge results, streaks, favorites, statistics and settings.
- Device and app information: device model, operating system and version, app version, language, network type and IP address.
- Error logs: technical information about crashes and errors, linked to your User ID, so we can fix problems.
2.3 Advertising information
Ads are provided by Google AdMob. Depending on your choices and local law, Google may collect: your device's advertising identifier (IDFA on iOS, only if you allow tracking; the Android advertising ID on Android), IP address, device and app information, and information about ads shown and your interactions with them. See section 4 for your choices.
2.4 Purchase information
If you make a one-time in-app purchase, payment is handled entirely by Apple (App Store) or Google (Google Play). We receive only the information needed to deliver and restore your purchase: transaction or order ID, product, purchase date, and the store country or region. We link this to your User ID so the purchased feature works on your account.
2.5 What we do not collect
We do not collect your name, email address (unless you email us), phone number, contacts, precise location or payment card details.
3. How we use information
| Purpose | Information used | Legal basis (EEA/UK) |
|---|---|---|
| Provide the game: save progress, Daily Challenge, leaderboards, hints, share codes | User ID, game data, nickname, puzzles | Performance of our contract with you |
| Recognize puzzles with Photo Solve | Photos you choose | Performance of contract |
| Deliver and restore purchases | Purchase information, User ID | Performance of contract |
| Show ads that keep the app free | Advertising information | Consent (personalized ads); legitimate interests (non-personalized ads) |
| Keep the service secure, prevent fraud and abuse | Device and app information, IP address, logs | Legitimate interests |
| Fix bugs and improve the app | Error logs, device and app information | Legitimate interests |
| Comply with legal, tax and accounting obligations | Purchase information | Legal obligation |
4. Advertising and your choices
- Consent (EEA, UK, Switzerland and other regions where required): on first launch we show a consent message from Google's User Messaging Platform. You can change your choice at any time on the Me page under "Ad privacy settings".
- iOS tracking permission: the app asks for permission through Apple's App Tracking Transparency. If you decline, your IDFA is not shared. You can change this in Settings > Privacy & Security > Tracking.
- Android advertising ID: you can reset or delete it in your device's Google or Privacy settings.
- Ads are limited to content suitable for general audiences (maximum rating "PG").
- Learn how Google uses information from apps that use its services: policies.google.com/technologies/partner-sites.
5. Third-party services
| Service | Provider | Purpose | Privacy policy |
|---|---|---|---|
| Google AdMob and User Messaging Platform | Google LLC / Google Ireland Limited | Ads and ad consent | policies.google.com/privacy |
| App Store in-app purchases | Apple Inc. | Payment for purchases on iOS | apple.com/legal/privacy |
| Google Play Billing | Google LLC | Payment for purchases on Android | policies.google.com/privacy |
| Cloud hosting and storage | Alibaba Cloud | Hosts our servers and app content on our behalf | — |
| WeChat Open SDK (iOS only) | Tencent | Opens WeChat when you tap Customer Service; no data is sent unless you use it | WeChat privacy |
Note for iOS: the iOS app is a single build for all regions. It also contains advertising SDKs used only in mainland China (Pangle by ByteDance and Tencent Youlianghui). These SDKs are initialized only when your App Store account region is mainland China. For users in other regions they are not started and do not collect information.
We share information with service providers only as needed for the purposes above, and we require them to protect it. We may also disclose information when required by law or to protect rights and safety.
6. Device permissions
| Permission | Platform | When and why |
|---|---|---|
| Camera | iOS, Android | Only when you use Photo Solve to take a picture of a puzzle |
| Photos / media | iOS, Android | Only when you choose an existing image for Photo Solve |
| Tracking (App Tracking Transparency) | iOS | To ask whether your IDFA may be used for ads; optional |
| Advertising ID | Android | Used by AdMob for ads, subject to your settings and consent |
| Internet | iOS, Android | To sync progress, show leaderboards and ads, and use online features |
You can turn permissions off at any time in your device settings. The rest of the game keeps working.
7. Where information is stored
Our servers are located in mainland China and operated on Alibaba Cloud. When you use the app outside China, your information is transferred to and processed in China. Google and Apple may process information in other countries under their own policies. Where required (for example, transfers from the EEA or UK), we rely on appropriate safeguards such as standard contractual clauses.
8. How long we keep information
- Game data, User ID and nickname: while you use the app. If you ask us to delete your data, we delete it within 30 days, except where we must keep it by law.
- Photos for Photo Solve: kept for up to 3 months to recognize the puzzle and troubleshoot recognition problems, then deleted. They are not used for any other purpose.
- Error logs: up to 12 months.
- Purchase records: as long as required by tax and accounting laws.
Data stored only on your device, such as an unfinished game, is removed when you uninstall the app.
9. Your rights
Depending on where you live, you may have the right to access, correct, delete or receive a copy of your personal information, to object to or restrict certain processing, and to withdraw consent at any time without affecting earlier processing. These rights may arise under laws such as the EU/UK GDPR, the California Consumer Privacy Act, Japan's Act on the Protection of Personal Information, Korea's Personal Information Protection Act, Thailand's Personal Data Protection Act, Vietnam's Decree 13/2023 and Indonesia's Personal Data Protection Law.
To make a request, email us at the address below and include your Sudoku ID from the Me page so we can find your data. We respond within 30 days. You also have the right to complain to your local data protection authority.
California residents: we do not sell personal information. Personalized advertising through AdMob may be considered "sharing" under California law. You can opt out by declining tracking on iOS, deleting your Android advertising ID, or contacting us.
10. Children
The app is not directed to children under 13, or under the minimum age required in your country. We do not knowingly collect personal information from children. If you believe a child has provided us with personal information, contact us and we will delete it.
11. Security
We use reasonable technical and organizational measures to protect your information, including encrypted connections (HTTPS) and access controls. No method of transmission or storage is completely secure, but we work to protect your information and will respond to incidents as required by law.
12. Changes to this policy
We may update this policy as the app changes. We will post the new version on this page with a new effective date. If the changes are significant, we will also notify you in the app.
13. Contact us
Langfang Zilingxing Technology Co., Ltd.
Room 1702, Unit 1, Building 3, Plot 3, Huayu City, University Town, Langfang Economic and Technological Development Zone, Hebei, China
Email: zhaoqi_accp@163.com