Privacy Policy

Overview

Sudoku Master ("we", "our", or "us") is a mobile puzzle game available on Android and iOS. We are committed to protecting your privacy and being transparent about what data we handle.

This Privacy Policy applies to the Sudoku Master mobile application (the "App") and our website at soduku-master.firebaseapp.com. By downloading or using the App, you agree to the practices described in this policy.

We built Sudoku Master to be a privacy-friendly game: no account registration is required, your game progress is saved locally on your device, and we only collect data that is strictly necessary to operate and improve the App. Features such as the Daily Challenge Leaderboard are entirely opt-in and require only a display name of your choosing.

Information We Collect

We collect the following categories of data:

Display Name: On first launch, the App asks you to choose a display name used solely for the Daily Challenge Leaderboard. This name is entirely your choice — it does not need to be your real name and can be a nickname or alias. If you skip this step, you can still play all features; your scores simply will not appear on the leaderboard.

We do not collect: your email address, phone number, precise location, contacts, photos, or microphone input. No account registration or password is required to use any feature of the App.

How We Use Your Data

We use the data we collect for the following purposes:

• App Analytics: To understand how players interact with the App — which difficulty levels are most popular, how often hints are used, and how we can improve the overall experience.
• Crash Reporting: To detect, diagnose, and fix technical issues quickly. Game context (difficulty, elapsed time) is attached to crash reports solely to help reproduce and resolve bugs.
• Remote Configuration: To remotely enable or disable features (e.g., ad types, hint availability) without requiring an app store update.
• Push Notifications: To send a once-daily reminder notification when a new Daily Challenge puzzle is available. You can disable notifications at any time in your device Settings.
• Daily Challenge Leaderboard: To display your chosen display name and today's score on the shared leaderboard. Only the data you explicitly choose to submit is sent.
• Advertising: To display ads through Google AdMob (banner, interstitial, app open, and native formats) that help us keep the App free for everyone.
• App Updates: To check whether your installed version is current and alert you to required or optional updates.
• App Store Reviews: After a win milestone is reached, the App may prompt you to rate it using the native Apple/Google review dialog. No data is sent to us as a result.
• In-App Purchases: To process and verify your one-time Premium upgrade through Apple App Store or Google Play. We use the purchase confirmation to unlock Premium features (ad removal, unlimited hints) on your device. We do not receive your payment details — all billing is handled by Apple or Google.

We do not use your data for automated decision-making, profiling, or any purpose beyond those listed above. We do not sell your data to any third party.

Third-Party Services

The App integrates the following third-party SDKs and services. Each operates under its own privacy policy:

All Firebase and AdMob services are operated by Google LLC and subject to Google's Privacy Policy. We have no control over data Google collects through these SDKs beyond the configuration we apply.

Advertising & Ads

Sudoku Master is a free app supported by advertising. We use Google AdMob to display the following ad formats:

• Banner Ads — displayed at the bottom of the Home and Game screens.
• Interstitial Ads — full-screen ads shown when returning to the Home screen from a game. A minimum 3-minute cooldown is enforced between displays.
• App Open Ads — shown when the app is launched or foregrounded. A minimum 4-hour cooldown is enforced, and no app open ad is shown on a user's very first install launch.
• Rewarded Video Ads — optional, user-initiated ads available in-game. Watching a rewarded ad grants the player an extra hint. These are never shown automatically; the player must choose to watch them.
• Native Ads — content-style ads blended into the Home screen feed.

All ad types can be individually enabled or disabled remotely via Firebase Remote Config, allowing us to respond quickly to any issues without requiring an app update.

Premium Upgrade: Users who purchase the Premium upgrade (one-time, non-recurring payment) will have all ad formats permanently disabled. No ads of any kind are shown to Premium users.

Personalised Ads (iOS): On iOS 14.5 and later, we request your permission via Apple's App Tracking Transparency (ATT) framework before showing personalised ads. If you decline, ads are still shown but will be non-personalised.

Personalised Ads (Android): Google AdMob uses your advertising ID (GAID) for personalised ads by default. You can opt out in device Settings → Google → Ads → Delete advertising ID or Opt out of Ads Personalisation.

Children: We do not knowingly show behavioural or interest-based ads to users under the age of 13. See Section 8 for our full children's privacy policy.

Data Sharing

We do not sell, trade, rent, or otherwise transfer your personal data to third parties except in the following circumstances:

• Service Providers: We share data with Google (Firebase Analytics, Crashlytics, Remote Config, Cloud Messaging, Firestore, AdMob) solely to operate and improve the App as described in this policy.
• Leaderboard: When you choose to submit a Daily Challenge score, your display name, score details, and anonymous device ID are stored in our Firebase database and displayed publicly on the in-app leaderboard. You are never required to submit a score.
• Legal Requirements: We may disclose information if required by law, court order, or governmental authority.
• Business Transfer: In the event of a merger, acquisition, or sale of assets, user data may be transferred to the new owner subject to the same privacy protections.

In all other cases, your data stays with us and our listed service providers only.

Data Retention

Different types of data are retained for different periods:

• Local game data (puzzle progress, statistics, daily challenge history) is stored on your device and remains until you uninstall the App or clear its data.
• Daily challenge history kept on-device is automatically trimmed to the last 60 days.
• Leaderboard scores are retained on our Firebase database indefinitely unless you request deletion.
• Firebase Analytics data is retained for 14 months per Google's default settings.
• Crashlytics crash reports are retained for 90 days.
• Firebase Remote Config does not store any personally identifiable data — it only delivers configuration values to the App.
• FCM push tokens are managed by Google and refreshed automatically; we do not store them independently.

You can request deletion of any server-side data associated with your device at any time by contacting us (see Section 12).

Children's Privacy

Sudoku Master is a puzzle game suitable for all ages. We take children's privacy seriously and comply with:

• The Children's Online Privacy Protection Act (COPPA) — United States
• The UK Children's Code
• The Google Play Families Policy
• Apple App Store Guidelines for apps available to children

We do not knowingly collect personally identifiable information from children under 13. The core game requires no personal information to play. The optional Leaderboard feature asks for a display name — parents or guardians should supervise this step for younger players.

We do not show behavioural or interest-based ads to users under 13.

The App offers a one-time Premium upgrade that removes ads and unlocks unlimited hints. This purchase is processed through Apple App Store or Google Play, both of which require parental approval for accounts belonging to children under 13 via their respective Family Sharing and Family Link controls. We do not independently verify the age of purchasers — parents and guardians are responsible for managing in-app purchase settings on their child's device.

If you believe we have inadvertently collected information from a child under 13, please contact us immediately at sky.techno.biz@gmail.com and we will delete it promptly.

Your Rights

Depending on your location, you may have the following rights regarding your data:

• Right to Access: Request a copy of the data we hold about you.
• Right to Deletion: Request that we delete your data. Local game data can be removed by uninstalling the App; server-side leaderboard data can be deleted on request.
• Disable Push Notifications: Go to your device Settings → Notifications → Sudoku Master and turn off notifications at any time.
• Opt Out of Ad Personalization:
  • iOS: Settings → Privacy & Security → Tracking → disable tracking for Sudoku Master.
  • Android: Settings → Google → Ads → Delete advertising ID or Opt out of Ads Personalization.
• Right to Withdraw Consent: Uninstall the App at any time to stop all data collection.
• GDPR (EU/EEA): Right to access, rectify, erase, restrict processing, and data portability. You may also lodge a complaint with your local data protection authority.
• CCPA (California): Right to know, delete, and opt out of the sale of personal information. We do not sell personal information.

To exercise any of these rights, contact us at sky.techno.biz@gmail.com.

Security

We take reasonable technical and organizational measures to protect the data we collect:

• All data transmitted between the App and Firebase servers is encrypted in transit using TLS/HTTPS.
• Firebase services run on Google's infrastructure, which holds ISO 27001, SOC 2, and SOC 3 certifications.
• Game data stored locally is protected by your device's own security model (app sandboxing and OS-level encryption at rest).
• Leaderboard entries contain only your chosen display name and puzzle performance data — no passwords or sensitive identifiers are stored.

While we take every reasonable precaution, no method of internet transmission or electronic storage is 100% secure. We will notify you of any material data breach as required by applicable law.

Changes to This Policy

We may update this Privacy Policy from time to time to reflect changes in our practices, technology, legal requirements, or app features. When we make material changes, we will:

• Update the "Last updated" date at the top of this page.
• Display a notice inside the App on your next launch for significant changes.

We encourage you to review this policy periodically. Your continued use of the App after changes are posted constitutes acceptance of the updated policy.

Contact Us

If you have any questions, concerns, or data requests regarding this Privacy Policy or how Sudoku Master handles your data, please reach out — we typically respond within 48 hours.