Privacy Policy

Effective 19 October 2026

Keyboard Mentor is a piano and keyboard learning app for iPhone, iPad and Android, operated by PlugAI ("we", "us"). This policy explains what the app and our servers collect, why, who else handles it, and the choices you have. We wrote it from what the app actually does.

1. Data we collect and why

Your account

• Anonymous account ID. When you first open the app, it creates an anonymous account with Google Firebase Authentication. The account has a random ID and no name or email. It lets you sign in later without losing anything, and it is what the coach uses to know a request comes from a real install.
• Sign-in details, if you choose to sign in. You can link Sign in with Apple, Google, or an email address and password. Firebase then stores your email address and, where the provider shares it, your name. With Sign in with Apple you can choose to hide your email address. Firebase manages your password; we never receive it in plain text.
• Why: so your purchases follow you to a new phone, and so the coach can check that you are entitled to it.

Subscriptions

• When you start a trial, subscribe or restore purchases, the payment is handled by Apple or Google. We never see your card details.
• Our subscription partner RevenueCat records your purchase history, store receipts, subscription status and basic device and store details (such as the app version, operating system, country and currency). Before you sign in, RevenueCat knows you only by a random ID it creates. After you sign in, the app links your purchases to your account ID so Pro follows you.
• RevenueCat tells our server when your subscription changes. Our server then stores a short record against your account ID or RevenueCat ID: whether Keyboard Mentor Pro is active, where that came from and when it was last updated, plus the IDs of the subscription events it has already processed.
• Why: to sell and unlock Keyboard Mentor Pro, restore it, and check it when you use the coach.

The coach (Pro)

The coach answers questions about your lessons and the app. It only runs when you open it and send a message. Each request goes over HTTPS to our server at https://api.guitarmentor.in (PlugAI's shared server) and contains:

• the messages in your current coach conversation (your questions and its earlier replies, up to the last 12, each cut to 2,000 characters);
• facts about your latest scored run of the lesson you are asking about, worked out on your device: the lesson name and ID, practice mode (Wait or Tempo), the input you used (touch, MIDI or microphone), score, stars, whether you passed, tempo, the number of notes and how many were wrong, missed, early or late, and up to three plain-language tips about your main mistakes;
• your account's sign-in token, which our server uses to confirm your account ID.

It does not contain audio, MIDI data, your email address, your age group or any other progress. Our server adds the app's own help text and passes the request to an AI provider (see section 3), which writes the reply. The app does not save coach conversations; they disappear when you close the coach.

To apply fair-use limits, our server keeps a daily count of your coach requests (your account ID, the date and the number of requests). It does not store the questions or answers.

Scores, stars and timings are always computed by the app on your device. The coach explains them; it never calculates or changes them.

Sound-pack downloads

If you tap Download full piano, the app downloads a sound file from our web host (https://guitarmentor.in). The request carries no account details. Like any web server, the host keeps standard access logs (IP address, time, file requested and the requesting software).

Server logs

When the coach or a subscription update runs, our server keeps short technical logs, for example the time of a request and, when something fails, your account ID and the type of error. Server errors may also be reported to our error-monitoring service, Sentry. These logs are used only to keep the service working and are deleted on our hosting providers' standard schedules.

2. Data kept only on your device

The following never leaves your device (except the coach facts listed above, and only when you send a coach message):

• Microphone sound. In Listen mode and during microphone calibration, the app listens to your piano and works out which note you played, live, on the device. Audio is not recorded, saved or uploaded. You can turn off microphone access in your phone's settings; the app then works with touch or MIDI.
• MIDI. Notes from a USB or Bluetooth MIDI keyboard are read and scored on the device. The app lists the names of connected MIDI devices so you can pick one; that list stays on the device. On Android 11 and older, Bluetooth scanning needs the Location permission; the app does not read or use your location.
• Learning data. Lessons passed, run history (score, stars, accuracy, timing, input and mode), streaks, badges, certificates, practice minutes, songs, skipped lessons and placement results.
• Settings and onboarding answers. Who is learning (child, teen or adult), whether you read music, your goals, preferred genres, daily minutes, input choice, notation settings, timing calibration and reminder time.
• Reminders. Practice and trial reminders are local notifications scheduled on your phone. We do not use push notifications and do not collect a push token.
• Downloaded sound packs.

This data is stored in the app's private storage on your device. It is not backed up to our servers and does not sync between devices. Deleting the app, or using Profile → Reset progress, removes it.

3. Data we do not collect

• No audio recordings, and no audio sent anywhere.
• No analytics or usage tracking SDK, and no crash-reporting SDK in the app.
• No advertising, no advertising identifier (IDFA or Android Advertising ID), and no tracking across other companies' apps or websites.
• No location, contacts, photos or camera.
• No payment card details.
• No date of birth. The age group you pick during setup stays on your device.

We do not sell your personal data, and we do not share it for advertising.

4. Third parties that process data for us

The AI provider that answers coach requests may change; this page will name the current ones. We do not send AI providers your email address, account ID, audio or advertising identifiers.

Shared sign-in with PlugAI's other app. Keyboard Mentor uses the same Firebase sign-in system and server as another PlugAI app. If you sign in to both apps with the same Apple, Google or email account, it is the same account in both. Keyboard Mentor Pro and the other app's subscription are kept separate, and Keyboard Mentor does not read your data from the other app.

5. How long we keep data

• On your device: until you reset progress, delete the app, or (for downloaded sounds) delete the pack.
• Your sign-in account: until you delete it.
• Pro status record and processed subscription event IDs on our server: while your account exists, until in-app or email deletion (see section 6).
• Daily coach usage counts: each count is only a number for one day and expires separately.
• Purchase records at Apple, Google and RevenueCat: as those companies and tax and accounting law require.
• Server and web logs: on our hosting providers' standard retention schedules.

6. Deleting your account

In the app, go to Profile → Account → Delete account, type DELETE and confirm. This permanently deletes your sign-in account, Pro status record, processed Keyboard Mentor subscription event IDs and RevenueCat customer record. The app then starts a new, empty anonymous account. Progress on your device is not touched; use Profile → Reset progress or delete the app to remove it.

Daily coach usage counts are not deleted by the in-app flow. Each is only a number for one day and expires separately. If you can no longer open the app, email admin@plugai.in from the address you signed in with; we complete deletion within 30 days. Deleting your account does not cancel a subscription: cancel it in your App Store or Google Play settings. Full steps are on the delete account page.

Because the sign-in system is shared, deleting the account also deletes it for PlugAI's other app if you used the same sign-in there.

7. Children

Keyboard Mentor has a kids mode for learners aged 4 to 10, which a parent or carer turns on during setup or in Profile → Learner. The app shows no ads in any mode and contains no analytics or advertising SDKs.

• Your child's age group is stored only on the device.
• In kids mode, purchases, restoring purchases, signing in, account actions such as sign-out and deletion, opening the coach, and leaving kids mode all sit behind a grown-up check.
• The app creates the same anonymous account ID for every install, including in kids mode, so that purchases and the coach can work. It carries no name or contact details.
• The coach is a Pro feature. If a child sends it a message, the message and the run facts go to our server and AI provider as described in section 1. Please supervise a child's use of the coach.

We do not knowingly collect personal information from a child beyond what is described here. If you believe a child has given us personal information, for example by signing in with an email address, email admin@plugai.in and we will delete it.

8. Security

• All traffic between the app and our server, Firebase, RevenueCat and the sound-pack host uses HTTPS.
• Our server accepts coach requests only with a valid Firebase sign-in token, and checks Pro status on the server.
• Passwords are handled by Firebase and never reach us in plain text.
• Access to our server, database and logs is limited to the people who run the service.
• Sound packs are checked against a published checksum before the app uses them.

No system is perfectly secure, but we work to protect your data and will tell you if a breach affects you, as the law requires.

9. Your rights

Depending on where you live, including under India's Digital Personal Data Protection Act, 2023, the EU and UK GDPR, and US state privacy laws, you can ask us to:

• tell you what personal data we hold about you and give you a copy;
• correct it;
• delete it (see section 6);
• stop a use you previously agreed to, such as sign-in or the coach (stop using it and delete the account);
• nominate someone to act for you, where the law allows.

You can also turn off microphone, Bluetooth and notification permissions in your phone's settings at any time. Email admin@plugai.in to use any of these rights. We reply within 30 days. If you are not satisfied, you may complain to your local data protection authority (in India, the Data Protection Board of India).

Our server and providers are located in the United States and other countries, so your data may be processed outside the country where you live. We rely on our providers' standard safeguards for those transfers.

10. Changes to this policy

We will update this page when the app changes how it handles data, and change the effective date above. If a change significantly affects how your data is used, we will also tell you in the app.

11. Contact

PlugAI, operator of Keyboard Mentor
Email: admin@plugai.in
Help with the app: Keyboard Mentor support