Kinor Privacy Policy

Last updated: September 17, 2026

Kinor is a violin study app. This page explains, in plain English, what the app stores, where it stores it and how to delete it.

The company responsible for the app and for this policy (the controller, under the GDPR, the UK GDPR and Brazil's LGPD) is Barukel Systems LTDA, a company registered in Brazil (CNPJ 63.183.072/0001-31), Rua Inconfidência, 510, Sala 103, Centro, 32600-100 Betim – MG, Brazil. Contact: contato@barukel.com.br.

1. In one sentence

Kinor has no sign-up and does not ask for your name, email or any other personal details. Your progress stays on your device. So that a subscription works on one device at a time, the app sends Barukel's server only what is needed to check the purchase.

2. What stays on your device

• Your progress: points, level, stars, game records and practice streak.
• The name you choose to display, if you choose one. It is optional, can be a nickname and is shown only to you.
• Your preferences: light or dark theme and the app language.
• Whether your subscription is active, so the app opens even without an internet connection.
• A random code for this installation and the date the subscription was last confirmed (section 6).

Your progress, name and preferences never leave the device, and we have no access to them. That is why switching phones starts your progress from scratch.

3. Microphone

The app uses the microphone in the tuning exercises and when it gives feedback on a melody you play.

Audio is never recorded or sent anywhere. It is processed in real time, on your device only, and then discarded. No audio file exists, and nobody can listen to what was played.

Permission is requested only when you open one of these activities, and you can refuse it: the rest of the app keeps working.

4. Voice

Some lessons read text aloud using your device's own text-to-speech engine (the same one the system uses for accessibility). Kinor does not send this text to any service.

5. Subscription and payment

Part of the content is free; the rest requires a monthly subscription. The store charges you — Google Play on Android or the App Store on iPhone — through the subscriber's store account.

• We do not receive card numbers, addresses or any other payment data. The store tells the app whether the subscription is active.
• Payment, cancellation and refunds follow the store's rules and privacy policy.

6. One subscription, one device

A subscription works on one device at a time (Terms of Use). To make that possible:

• What is sent: a random code created by the app when it is installed (it does not contain your name or contact details) and the purchase receipt that the store gives the app. No name, email or progress.
• When: when you open the app and when you open a paid lesson or exercise. While the app is open on screen, it keeps a connection to the server so it knows right away if the subscription is being used on another device. When the app is closed or in the background, there is no connection.
• What we keep: which device code is using each purchase, the expiry date the store confirms and the dates of use. To confirm the purchase, our server checks the receipt with Google Play or the App Store. Like any server, ours receives your IP address with each request; we use it only in memory, for about a minute, to limit excessive requests, and we do not store it in logs or in the database.
• Why: to enforce the Terms of Use (one subscription per device). Legal basis: performance of the contract you entered into when subscribing (Article 6(1)(b) of the GDPR and of the UK GDPR). We do not use it for advertising, and we do not share it with anyone other than the services described in section 7.
• Where: Barukel's server on Amazon Web Services in São Paulo, Brazil, encrypted. Barukel is established in Brazil and receives this data directly from the app, so it is processed in Brazil.
• For how long: while the subscription exists; after that we delete it. Requests: by email to contato@barukel.com.br.

7. Third-party services

• Google Play (Android) and the App Store (iPhone) — charge for the subscription and tell the app whether it is active.
• On Android, Google's billing library, which handles this exchange with Google Play, sends Google technical information about how it is working, such as errors and response times. That information goes to Google, follows Google's privacy policy and never reaches us.
• Amazon Web Services, in São Paulo — hosts the server in section 6, as our processor.

The app has no ads, uses no usage analytics and does not share data with anyone for advertising. We do not sell or share personal information (as those terms are defined in the California Consumer Privacy Act), and we do not use it for automated decision-making or profiling.

8. Children and teenagers

Kinor is made for violin students of all ages, including children.

• We do not ask anyone for personal details, of any age: there is no sign-up, and the display name is optional and stays on the device.
• There are no ads, no chat, no content posted by other people and no links to social networks.
• The subscription is bought with an adult's store account. The stores offer parental controls — Google Family Link and Apple Family Sharing — that can require a parent's approval before any purchase.
• Because Kinor is meant for all ages, we treat every user as possibly being a child under 13. The only personal information the app handles is the installation code (a persistent identifier) and the purchase receipt in section 6. They are used solely to support the app's internal operations, that is, checking that the subscription is valid and used on one device at a time, and never for advertising, profiling or contacting anyone. A parent can ask us to delete them at contato@barukel.com.br.

9. How to delete

• Progress and name: uninstall the app, or clear its data in your device settings. No copy is left anywhere.
• The device record on the server (section 6): we delete it when the subscription ends; to delete it sooner, write to contato@barukel.com.br.
• The subscription: cancel it in Google Play or in the subscription settings of your Apple Account. Uninstalling the app does not cancel the subscription.

10. Your rights

Depending on where you live — for example, under the GDPR in the European Union, the UK GDPR in the United Kingdom, US state privacy laws such as the CCPA in California, or Brazil's LGPD — you, or a child's parent, have the right to access the personal data we hold, correct it, delete it, restrict its use and receive it in a portable format. What we keep is only the installation code and the purchase receipt (section 6); to exercise any of these rights, write to contato@barukel.com.br. We reply within 15 days. We will not treat you differently for exercising your rights.

Because there is no account, we may ask for your store order number so we can find the record that belongs to you. We honor these rights for everyone, wherever you live.

You also have the right to lodge a complaint with the data protection authority of the country where you live or work (in the UK, the Information Commissioner's Office). In Brazil, you can contact the ANPD (Autoridade Nacional de Proteção de Dados).

11. Security

Your progress stays only on the device, protected by the operating system (Android or iOS), and the app has no cloud backup. Communication with the store is handled by the store itself and is encrypted, and communication with Barukel's server is also encrypted (HTTPS).

12. Changes to this policy

If anything changes, the date at the top of this page changes with it. We will let you know about significant changes in the app.

Contact

Barukel Systems LTDA — responsible for Kinor contato@barukel.com.br