Privacy Policy

1. Who we are

This Privacy Policy applies to the Twin Sudoku app for mobile devices (the “Application”), published by HKV Studios (“HKV Studios”, “we”, “us”). HKV Studios is responsible for the Application and is the data controller for the limited information described here.

By installing or using the Application you agree to this policy. Where the law requires your consent (for example, for personalised advertising), we ask for it separately inside the Application.

2. What stays on your device

The Application saves your progress so that closing the game does not send you back to Level 1. It uses your device's standard app-preferences storage and writes only these values:

• Level reached · the level you are currently on.
• Unfinished level · the tiles you have placed on your current level, your remaining hearts, your undo steps and the time played, so you can carry on where you left off. It is deleted when you finish or lose that level. Custom boards are never saved.
• Hints remaining · how many of today's free hints you have left, and the date they belong to.
• Settings · whether music, sound effects and vibration are on.
• Notification prompt · whether the game has already asked for permission to send reminders.
• Last full-screen ad · when the last full-screen ad was shown, so ads are spaced at least two minutes apart.

These values never leave your device and are never sent to us. They are deleted when you clear the app's data or uninstall the Application. Device backup services such as Google backup may include them in your personal backup, under the terms of that service.

3. Information collected automatically

HKV Studios does not run its own servers for the Application and does not receive your personal information. However, the Application includes software development kits (SDKs) from the third parties listed in section 5. When the Application runs, these SDKs may automatically collect:

• Device and advertising identifiers: the Google Advertising ID (AAID), Google App Set ID, and on iOS the IDFV and, only if you allow tracking, the IDFA.
• Device information: device model and manufacturer, operating system and version, screen size, language, time zone, mobile carrier and network type.
• Approximate location: your country or region, estimated from your IP address. The Application never uses GPS or precise location.
• Ad interaction data: which ads were shown, whether you tapped them, how long a video ad played, and whether an ad led to an app install.
• Ad SDK diagnostics: app launch time, ad load times and errors, and SDK performance data such as hang rate and energy use.
• Installed apps: information about some other apps installed on your device. The advertising SDKs use it to avoid showing ads for apps you already have and to detect fake installs and bot traffic.

The Application does not include any analytics or crash-reporting service. The only data leaving your device is what the advertising SDKs in section 5 collect.

4. How information is used

Information collected through the Application is used to:

• show ads, including personalised ads where you have agreed to them, and keep the game free;
• limit how often you see the same ad, and detect and prevent ad fraud;
• measure how ads perform and pay the networks that deliver them;
• diagnose ad loading problems so ads do not slow down or break the game;
• record your advertising consent choices where the law requires them;
• meet our legal obligations and respond to lawful requests.

5. Third-party services

The Application uses the following third-party services. Each one collects and processes data under its own privacy policy, which we recommend reading.

If we add another ad network in future, we will list it here before it starts serving ads in the Application.

6. Advertising and consent

Twin Sudoku is free to play and is funded by ads: a banner below the board, full-screen ads between levels, and optional rewarded videos. A rewarded video gives you an extra hint once your free hints for the day are used, or an extra heart when you run out of hearts. You never have to watch a rewarded ad to keep playing. Full-screen ads are spaced at least two minutes apart.

Personalised and non-personalised ads

Personalised ads are chosen using your advertising ID and your activity in other apps. Non-personalised ads are chosen only from general context such as your country and the app you are using, but still use your device data for frequency capping, fraud prevention and measurement.

Consent in the EEA, UK and Switzerland

If you are in the European Economic Area, the United Kingdom or Switzerland, the Application asks for your consent before any personalised advertising. The consent message is provided by Google's User Messaging Platform, which follows the IAB Transparency & Consent Framework. If you decline, you will see non-personalised ads only. To change your choice later, use Ad privacy choices in the game's Settings (the gear icon), or clear the Application's data (see section 11) so the consent message appears again the next time you open the game.

iOS App Tracking Transparency

On iOS, the Application asks your permission before accessing the IDFA. If you choose “Ask App Not to Track”, the IDFA is not shared and ads are not personalised using cross-app tracking.

Cookies and similar technologies

The Application does not use browser cookies. The advertising SDKs use device identifiers and local storage in a similar way: to remember your consent choices, cap ad frequency and measure ads.

7. App permissions

The Application requests these Android permissions:

• INTERNET and ACCESS_NETWORK_STATE: to load ads and show the consent message.
• com.google.android.gms.permission.AD_ID: to read the Advertising ID for ads, as described above.
• POST_NOTIFICATIONS: to send daily puzzle reminders (in the morning and evening). The game asks for this only after you finish your first level, and you can refuse or turn it off later in your device settings under Settings → Apps → Twin Sudoku → Notifications.
• RECEIVE_BOOT_COMPLETED: to restore those reminders after your phone restarts.

Reminders are created and scheduled on your device. They are not sent from a server, contain no ads, and use no notification token or identifier.

Some libraries in the Application add a few more permissions automatically: VIBRATE (notifications), WAKE_LOCK and FOREGROUND_SERVICE (background tasks used by the ad SDKs), and ACCESS_ADSERVICES_ATTRIBUTION / ACCESS_ADSERVICES_TOPICS (Android's privacy-preserving ad measurement, used by Unity Ads where available). None of these give access to your personal files or accounts.

The Application does not request access to your camera, microphone, location, contacts, photos or files.

The Application does not request the QUERY_ALL_PACKAGES permission, and our own code never reads the list of apps on your device. The advertising SDKs, however, can see some installed apps that Android makes visible to them, and send that information directly to the ad network, for choosing relevant ads and preventing fraud. It never reaches HKV Studios. You can limit its use for personalised ads by deleting or resetting your advertising ID (see section 11).

8. Sharing and disclosure

Information collected through the Application is shared only:

• with the advertising partners listed in section 5, for the purposes described there;
• when required by law, a court order or a valid request from a public authority;
• to protect the rights, property or safety of HKV Studios, our players or others, including to investigate fraud;
• with a successor, if HKV Studios or the Application is involved in a merger, acquisition or sale of assets. This policy would continue to apply.

We do not sell personal information for money.

9. International transfers

Our partners may process data in countries other than your own, including the United States. Where data leaves the EEA or UK, these partners rely on legal safeguards such as the European Commission's Standard Contractual Clauses or the EU–US Data Privacy Framework.

10. Data retention

• On your device: game progress and settings are kept until you clear the app's data or uninstall the Application.
• With our partners: each partner keeps the data it collects for the period set out in its own privacy policy.
• Emails to us: kept only as long as needed to answer your request, and deleted within 12 months.

11. Opt out and delete your data

Turn off personalised ads

• Android 12 and later: open Settings → Google → Ads (on some phones Settings → Privacy → Ads) and tap Delete advertising ID.
• Older Android: in the same place, turn on Opt out of Ads Personalization, or tap Reset advertising ID.
• iOS: open Settings → Privacy & Security → Tracking and turn tracking off for Twin Sudoku.

Turn off reminders

• Open Settings → Apps → Twin Sudoku → Notifications and turn notifications off.

Delete what the game stores

• Open Settings → Apps → Twin Sudoku → Storage and tap Clear data, or simply uninstall the Application. This deletes your progress and settings permanently.

Data held by our partners

We keep no copy of your data on our own servers, so there is nothing for us to delete on our side. Resetting or deleting your advertising ID cuts the link between your device and the data partners already hold. You can also contact each partner using the links in section 5. If you need help, email us and include your advertising ID if you have it, and we will pass your request to the relevant partners.

12. Your rights

Depending on where you live, you may have the right to access the personal data held about you, correct it, delete it, restrict or object to its use, receive a copy in a portable format, and withdraw consent at any time. Withdrawing consent does not affect processing that happened before.

EEA and UK: we rely on your consent for personalised advertising. We rely on our legitimate interests for non-personalised ads, ad measurement and fraud prevention. You may complain to your local data protection authority.

India: under the Digital Personal Data Protection Act, 2023, you may ask for a summary of your personal data, its correction or erasure, and you may raise a grievance with us using the contact details below.

To use any of these rights, contact us at the address in section 17. We answer within 30 days.

13. United States privacy rights

Residents of California and other US states with privacy laws have additional rights. In the last 12 months, the Application's partners have collected these categories of personal information: identifiers (advertising ID, IP address), internet or other electronic network activity (ad interactions, app usage, installed apps), approximate geolocation, and inferences drawn by ad partners about likely interests.

We do not sell personal information for money. Letting ad partners use your advertising ID for personalised ads may count as “sharing” for cross-context behavioural advertising under California law. You can opt out by deleting or resetting your advertising ID as described in section 11, or by contacting us. We will not treat you differently for using any of these rights.

14. Children

The Application is not directed at children under 13, or under the minimum age for digital consent in your country (up to 16 in parts of the EEA). We do not knowingly collect personal information from children. If you are a parent or guardian and believe your child has provided personal information through the Application, contact us and we will help remove it from our partners' systems.

15. Security

Your game data is protected by your device's own app sandbox. Our partners transmit data using encrypted connections (HTTPS) and protect it with their own safeguards. No method of storage or transmission is completely secure, but we choose partners that follow industry-standard security practices. If we learn of a security incident affecting your information, we will notify affected users and authorities as the law requires.

16. Changes to this policy

We may update this policy when the Application or the law changes. The new version will be posted on this page with a new effective date. If the changes are significant, we will also tell you inside the Application. Continuing to use the Application after an update means you accept the revised policy.

17. Contact us

For questions about this policy, privacy requests or grievances, contact:

HKV Studios
Email: hkvstudios@gmail.com

We aim to reply within 30 days.