Privacy Policy for Lazy Sudoku
Last Updated: 24 December 2024
Our Philosophy
Lazy Sudoku is built on the principle of "working smarter, not harder." This extends to privacy: we collect only what's necessary to make the app work well, and we're transparent about what we do collect.
We're a premium, ad-free sudoku application. We don't sell your data. We don't show you advertisements. We just want to help you solve sudoku puzzles.
Information We Collect
Information Stored Locally on Your Device
All puzzle data, progress, preferences, and settings are stored locally on your device. This includes:
- Your puzzle solving progress and history
- Custom puzzles you create
- Your app preferences and settings
- Puzzle bookmarks and favourites
We do not have access to this data. It never leaves your device unless you explicitly choose to use cloud sync (see Future Features below).
Purchase and Subscription Information
When you purchase a subscription, we use RevenueCat to process your transaction. RevenueCat collects:
- An anonymous app user identifier (a random UUID we generate)
- Your purchase and subscription status
- Device information (device type, OS version, app version)
- IP address (for fraud prevention)
This information is necessary to:
- Verify your subscription across devices
- Prevent unauthorised access to premium features
- Comply with app store requirements
RevenueCat is GDPR and CCPA compliant. You can read their privacy policy at: https://www.revenuecat.com/privacy
Crash Reports
We use Sentry to collect crash reports when the app unexpectedly closes. This helps us fix bugs and improve stability. Crash reports include:
- Device information (device type, OS version, app version)
- Stack traces showing where the crash occurred
- App state at the time of the crash
We do not collect: puzzle content, user preferences, or any personally identifying information in crash reports. IP addresses are anonymised before storage.
You can read Sentry's privacy policy at: https://sentry.io/privacy/
Analytics
We use Plausible Analytics to understand how the app is used. Plausible is privacy-first and doesn't use cookies or collect personal data. We collect:
- Anonymous usage statistics (which features are used)
- Generic device information (iOS vs Android, app version)
- General geographic region (country level only)
We do not collect: individual user behaviour, personally identifying information, or precise location data.
Plausible is GDPR, CCPA, and PECR compliant. You can read their data policy at: https://plausible.io/data-policy
Future Features (Not Yet Implemented)
Cloud Sync (Planned)
We plan to offer optional cloud synchronisation using platform-provided cloud storage (iCloud for iOS, Google Drive for Android). If you choose to enable cloud sync:
- Your puzzle progress and custom puzzles will be synchronised across your devices
- This data is stored in your cloud storage account (iCloud or Google Drive)
- The data is encrypted by Apple or Google, not by us
- We do not have access to your cloud storage
- You can disable sync at any time in app settings
This feature will be clearly marked as optional and requires your explicit consent.
Puzzle Scanning (Planned)
We plan to offer optical character recognition (OCR) to scan physical sudoku puzzles. Our goal is to implement this entirely on-device, meaning the image never leaves your phone.
If on-device processing proves insufficient, we may offer server-side OCR as a fallback. If we implement server-side processing:
- Puzzle images would be sent to our server for processing
- Images are processed immediately and deleted
- We do not store, analyse, or retain scanned images
- This will be clearly disclosed before you use the feature
We'll update this privacy policy before implementing any server-side OCR processing.
Online Puzzle Database (Planned)
We're building an online database of puzzles with rich metadata. Accessing this database will not require creating an account:
- Requests are authenticated using cryptographic signatures
- No personal information is collected or stored
- We cannot track individual users accessing the database
If we later offer user accounts for the web version of our puzzle database, that will be entirely optional and will have its own privacy controls.
What We Don't Do
- No advertising networks: We never have and never will integrate advertising SDKs
- No data brokers: We don't sell, rent, or share your data with third parties
- No tracking across apps or websites: We don't participate in cross-app tracking
- No location tracking: We don't collect your precise location
- No contact harvesting: We don't access your contacts, photos, or other personal information
Your Rights
Access and Deletion
Since most data is stored locally on your device:
- To delete puzzle data: Uninstall the app or use the "Clear Data" option in app settings
- To delete crash reports: Contact us at privacy@lazy-sudoku.online
- To delete analytics data: Plausible doesn't collect personal data, so there's nothing to delete
Subscription Data
For subscription-related data stored by RevenueCat:
- You can request deletion of your purchase data
- Contact us at privacy@lazy-sudoku.online with your request
- Note that deleting purchase history may affect subscription verification
GDPR Rights (EU Users)
If you're in the European Union, you have additional rights:
- Right to access: Request what data we hold about you
- Right to rectification: Correct inaccurate data
- Right to erasure: Request deletion of your data
- Right to data portability: Receive your data in a structured format
- Right to object: Object to data processing
Contact us at privacy@lazy-sudoku.online to exercise these rights.
CCPA Rights (California Users)
If you're in California, you have the right to:
- Know what personal information we collect
- Know whether we sell or share personal information (we don't)
- Opt out of the sale of personal information (not applicable)
- Request deletion of personal information
- Non-discrimination for exercising your rights
Children's Privacy
Lazy Sudoku is appropriate for users of all ages. We do not knowingly collect personal information from children under 13 (or the applicable age in your jurisdiction).
Since we collect minimal data and don't require account creation:
- Children can use the app without providing any personal information
- Parental consent is only needed for in-app purchases (handled by the App Store)
- We don't have special child-specific features that collect additional data
If you're a parent and believe your child has provided us with personal information, please contact us at privacy@lazy-sudoku.online.
International Data Transfers
Our service providers (RevenueCat, Sentry, Plausible) may process data in various countries. All providers are GDPR compliant and use appropriate safeguards for international data transfers, including:
- Standard contractual clauses
- Privacy Shield frameworks (where applicable)
- Data processing agreements
Changes to This Policy
We'll update this privacy policy when we add new features or change how we handle data. We'll notify you of significant changes through:
- An in-app notification
- Updating the "Last Updated" date at the top of this document
Continued use of the app after changes indicates acceptance of the updated policy.
Data Retention
- Local data: Retained until you delete it or uninstall the app
- Crash reports: Retained for 90 days, then automatically deleted
- Analytics data: Retained for 24 months in aggregate form only
- Purchase data: Retained as long as your subscription is active, plus necessary periods for legal compliance (typically 7 years for financial records)
Security
We take reasonable precautions to protect your information:
- All network communications use TLS encryption
- Purchase processing is handled by App Store/Play Store (we never see payment details)
- Crash reports are transmitted over encrypted connections
- We follow industry-standard security practices for our infrastructure
However, no method of transmission over the internet is 100% secure. While we strive to protect your information, we cannot guarantee absolute security.
Third-Party Services Summary
| Service | Purpose | Data Collected | Privacy Policy |
|---|---|---|---|
| RevenueCat | Purchase processing | Device ID, purchase status, IP address | Link |
| Sentry | Crash reporting | Device info, stack traces (anonymised) | Link |
| Plausible | Analytics | Anonymous usage statistics | Link |
Contact Us
If you have questions about this privacy policy or how we handle your data:
Email: privacy@lazy-sudoku.online
Website: https://lazy-sudoku.online
For general support questions, you can also reach us at support@lazy-sudoku.online.
Legal Entity
Lazy Sudoku is developed and operated by:
Sergei Fedorov pr Računarsko programiranje Beograd Studentski trg 4/7 Stari Grad, Beograd, 11000 Serbia
Summary for the Impatient
What we collect:
- Puzzle data (stored locally on your device only)
- Purchase info (to verify your subscription)
- Crash reports (to fix bugs)
- Anonymous usage statistics (to improve the app)
What we don't collect:
- Personal information
- Location data
- Contacts or photos
- Anything we don't need
Third parties:
- RevenueCat (purchases)
- Sentry (crash reports)
- Plausible (privacy-friendly analytics)
Your rights:
- Delete your data anytime
- Opt out of analytics (contact us)
- Full GDPR/CCPA rights for EU/California users
Questions? privacy@lazy-sudoku.online