Privacy Policy

Data controller and policy scope

This is the official privacy policy for SudoStep: Sudoku Coach (com.blacksunset.sudostep). The app publisher and controller for Blacksunset-managed processing described here is Blacksunset OÜ (Estonian registry code 16513658), trading as Blacksunset Studio.

Address: Hariduse põik 1, Kõrveküla alevik, Tartu vald, Tartu maakond, 60512, Estonia. Privacy contact: info@blacksunset.ee. App support: support@blacksunset.ee.

The app-specific sections below explain the device data and features the app accesses, the purposes of processing, external service providers, and retention and deletion practices.

When the app connects to external services named below, data is protected in transit with HTTPS or TLS. Data stored on the device can be managed and deleted using the options described below.

The app does not offer account creation, so an account-deletion request flow does not apply.

If you email support, Blacksunset OÜ processes your email address and message content to answer the request and resolve the issue. Support correspondence is kept only as long as necessary for support and applicable legal obligations.

Purpose of the app

SudoStep is a classic 9 x 9 Sudoku game and learning tool. It provides generated puzzles, a daily puzzle, custom puzzle entry, solving tools, lessons, explainable hints, and local progress statistics.

The app is sold as a paid download. It contains no advertising, subscription, virtual currency, or in-app purchase system.

Data stored locally

Settings, theme and language choices, active puzzle state, entered digits, pencil marks, colour marks, undo and redo history, elapsed time, mistakes, hint use, completion history, and local statistics are stored only in the app's private storage on your device.

SudoStep does not create an account, require login, or send this information to a SudoStep or Blacksunset Studio server.

Android automatic app-data backup is disabled for SudoStep.

Network access and third-party services

The Android app does not request the INTERNET permission and has no developer-operated backend, cloud sync, advertising SDK, analytics SDK, crash-reporting SDK, social login, or tracking technology.

The bundled Sudoku generator and solving logic run locally on the device. They do not transmit puzzle or usage data.

If you obtain SudoStep through Google Play, Google may independently process purchase, payment, licensing, download, install, Play Protect, and store diagnostic information under Google's own terms and privacy policy.

Payments

The one-time app price is processed by Google Play. SudoStep does not include in-app billing and Blacksunset Studio does not receive your payment-card details.

Google may retain transaction and licensing records as required for purchases, refunds, fraud prevention, accounting, and legal compliance under Google's policies.

Retention and deletion

Local app data remains on the device until you clear SudoStep's storage in Android settings or uninstall the app.

Because SudoStep has no account or developer cloud database, there is normally no app-specific user record held by Blacksunset Studio to delete. Google-controlled Play purchase and store data must be managed through Google's account and privacy controls.

Permissions, children, and contact

SudoStep does not request location, camera, microphone, contacts, storage, notification, advertising ID, or other sensitive Android permissions.

SudoStep is intended for a general audience and is not specifically directed to children under 13. It does not create child profiles or knowingly collect children's personal information.

Privacy and support questions can be sent to support@blacksunset.ee.