Study Coach

Privacy Policy

Last updated: October 4, 2026 · Developer: Lumii (Taner Sezer, Türkiye)

This policy explains what data the Study Coach app (known as DersKoçu in Türkiye; the "App") processes, where it is stored and how it is protected. The App is a study companion for middle and high school students: lessons, quizzes, flashcards, a planner and AI-assisted problem solving. By using the App you agree to this policy.

1. Data controller

The data controller under Turkey's Personal Data Protection Law (KVKK, No. 6698) and the EU General Data Protection Regulation (GDPR) is Lumii, Taner Sezer, Türkiye. Contact: sezerta@gmail.com

2. Account and Sign in with Apple

Most of the App (lessons, quizzes, flashcards, planner, focus timer, math practice) works without an account and offline. Signing in is needed only for Advanced AI and for syncing your progress; Basic AI needs no account.

The only sign-in method is Sign in with Apple. Apple sends us an Apple user identifier; if you choose to share them, your name and e-mail address as well. You may use "Hide My Email". We never store a password.

You can delete your account from inside the App (account section); see section 9.

3. Data stored on our server

When you create an account, the following is stored on a server we operate (Netcup data centre, Nuremberg, Germany, European Union):

The content of your chats is not stored on our server. Only token counts and wallet records are kept. Your chat history stays on your device.

4. AI: Basic AI (on your device) and Advanced AI (Anthropic)

Basic AI runs entirely on your device using Apple's on-device model (Apple Intelligence). Your questions and its answers are processed on the device and are not sent to our server or to any third party (including Anthropic and Google); it needs no account or internet connection, and the chat stays on your device. After 3 free messages you can watch an optional rewarded ad (see section 7) to unlock 3 more. As a small model it can make mistakes; the App says so below the answer.

Advanced AI answers are generated through an API provided by Anthropic (USA). To produce an answer, the text of your question, the last few chat messages and, if you use photo help, the photo you took or selected are sent to Anthropic. This is an international transfer of personal data under KVKK Art. 9 and GDPR Chapter V, based on the explicit consent you give by using Advanced AI.

Under Anthropic's API terms this data is not used to train models; retention is governed by Anthropic's privacy policy (anthropic.com/legal/privacy). Please do not put names, ID numbers, addresses or school numbers in your questions or photos.

5. Purchases

Token packs are one-time purchases made through Apple In-App Purchase (StoreKit). Apple processes the payment and we never see your card details. We verify the signed transaction we receive from Apple (transaction ID, product ID, date, environment) and record it in your wallet ledger to credit the tokens.

6. Data stored on your device

The camera and photo library are accessed only when you choose to take or pick a photo of a problem. The photo is sent to the AI provider to produce the answer and is not stored on our server.

7. Advertising (Google AdMob), tracking and analytics

The App has no banner or forced ads. You can choose to watch a rewarded ad to get an extra quiz attempt or 3 more Basic AI messages in the AI coach; an ad is shown only when you ask for it. We use Google AdMob for this, configured for children:

While serving an ad, AdMob may collect device identifiers (not used for advertising or tracking purposes), approximate location, advertising data (ad requests and interactions) and crash and performance data. This data is not used to track you across apps or websites. See policies.google.com/privacy.

There is no third-party analytics SDK, no location data of our own and we never sell your data.

8. Children

The App is aimed at middle and high school students, most of them between 11 and 18. We therefore take particular care:

9. Retention and account deletion

Server data is kept while your account exists. You can delete your account inside the App (account section, "Delete account"); alternatively e-mail sezerta@gmail.com. We delete your authentication record and all server rows, and any unused token balance is deleted with the account and cannot be restored. Deletion is completed within 30 days at the latest, including backups. Local data on your device is removed when you uninstall the App.

10. Legal basis and your rights (KVKK and GDPR)

We process data to perform our contract with you (providing the App), on our legitimate interest in running the service securely, and, for the transfer to the AI provider, on your explicit consent. You have the right to access your data, have it corrected or erased, object to processing, withdraw consent, learn who receives your data and complain to the Turkish Personal Data Protection Authority or the competent EU supervisory authority. Send requests to sezerta@gmail.com; we reply within 30 days.

11. Security

All connections use TLS. Server access is limited to authorised session keys and each user can reach only their own data. Session keys are kept in the iOS Keychain.

12. Changes

We may update this policy; the current version is always on this page with its date.

13. Contact

sezerta@gmail.com