Privacy Policy

The data controller is the operator of the Chronotika app. For any matters concerning the processing of personal data, you can contact us at chronotika@chronotika.com.

Registration and account data: email address, password in a secured (hashed) form (only when registering with email and password), an optional display name. When you register or sign in with Apple or Google, also the information the sign-in provider supplies to us — see section 3.

Study progress data: completed chapters, subchapters, and sections, quiz results, earned experience points (XP) and their award history, and your study streak.

Operational data: the date of your last activity in the app, your Chronotika Premium activation status, your notification settings, the language you use the app in and — if you allow notifications — your device's push notification token.

Nickname: if you use the leaderboard, the nickname you choose is shown to other learners together with the XP you earned that day or week. We never show your email address or account identifier to other learners. Until you choose a nickname, a temporary generated name is shown instead.

Feedback and requests: the text of a message (and, for lesson feedback, the lesson it refers to), if you voluntarily report a problem with a specific lesson or suggest a new course.

App usage data for analytics purposes: interactions with the app (e.g. opening a course, completing a chapter) and technical device identifiers, processed through the PostHog tool. These analytics events are linked to your account, including your account identifier, email address and display name.

Approximate location: when the app sends analytics events, PostHog derives your approximate location (country, region, and city) from the IP address of your device. We do not access your device's precise location (GPS).

Technical diagnostics: if the app hits an error or crashes, we send a technical error report through the Sentry tool (error type, app version, device model and operating system version, and the state of the app at the time) together with your account identifier. We do not attach your email address or display name to these reports.

We do not process or store your payment card details — payments for Premium are processed exclusively by the App Store or Google Play (see the Terms of Service). To manage subscriptions we use the RevenueCat service, which receives your Chronotika account identifier and information about your purchases and subscription status (product, price, dates, and whether the subscription is active). For accounting purposes we also keep a record of each paid transaction (transaction identifier, date, amount, and your email address).

Advertising measurement data: the app includes the Meta (Facebook) SDK, which we use to measure the effectiveness of our advertising. It sends Meta two events — that you completed registration (and by which method: email, Google, or Apple) and that you started a Premium subscription (with its price and currency) — together with technical device information such as the device model, operating system and app version, language, IP address, and device identifiers. On iOS, the advertising identifier is included, and the events are sent, only if you allow tracking in the system prompt shown by the app. On Android we do not enable collection of the advertising identifier. We do not send Meta your email address, name, study progress, or any other information about what you do in the app.

A user account can be created in three ways: with an email address and password, with Sign in with Apple, or with Sign in with Google. Signing in with Apple or Google is entirely optional.

When you register or sign in with Apple or Google, we process the information the identity provider supplies to us, typically: your email address, your name or display name, and a provider-specific account identifier. Google may also supply the URL of your profile picture. Apple may let you hide your real email address and give us a private relay address instead, and usually provides your name and email only the first time you authorize the app. To verify your sign-in, and to revoke the provider's access when you delete your account, we may also store technical tokens issued by the provider.

Google is used only for authentication — to confirm who you are. Chronotika does not access your Gmail, Google Drive, Google Calendar, Google Contacts, or any other Google service or data in your Google account, and does not request permission to do so. The same applies to Apple: we do not access any other data in your Apple ID.

We use the information received from Google or Apple only to create and manage your Chronotika account, to sign you in, and to communicate with you about your account. We store it in our database (MongoDB) together with the rest of your account data, keep it for as long as your account exists, and delete it when the account is deleted. We do not sell it, do not use it for advertising, and share it only with the processors described in the section “Who we share data with”.

We do not pass any data about your study progress or your activity in the app to Apple or Google as part of signing in. Chronotika's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including its Limited Use requirements. You can disconnect Chronotika from your Google or Apple account at any time in that provider's account settings.

Providing the service (registration and sign-in, maintaining your account, storing study progress, evaluating quizzes, managing Premium) — processing is necessary for the performance of the contract entered into by using the app (Art. 6(1)(b) GDPR).

Sending a daily study-streak reminder — only if you consent by enabling notifications and leaving the relevant toggle in the Account section switched on; you may withdraw consent at any time by turning off the toggle or disabling notifications in your phone's settings (Art. 6(1)(a) GDPR).

Sending occasional announcements as push notifications (for example about a new course) — only if you allow notifications in the system dialog; you may withdraw consent at any time by disabling notifications in your phone's settings (Art. 6(1)(a) GDPR).

Analyzing and improving the app — based on our legitimate interest in developing and improving the product (Art. 6(1)(f) GDPR).

Keeping the app stable and fixing errors (Sentry) — based on our legitimate interest in the app working reliably and errors being fixed quickly (Art. 6(1)(f) GDPR).

Measuring the effectiveness of our advertising (Meta SDK) — based on our legitimate interest in evaluating and improving our marketing (Art. 6(1)(f) GDPR). On iOS this happens only if you allow tracking in the system prompt, which you can change at any time in Settings → Privacy & Security → Tracking. You can object to this processing at any time (see section 8).

Handling submitted feedback and communicating with the user — performance of the contract, or alternatively our legitimate interest in improving the content.

Fulfilling legal obligations, for example in accounting matters relating to payments processed by the store (Art. 6(1)(c) GDPR).

We retain data associated with a user account for as long as the account exists. After an account is deleted, personal data is deleted or anonymized, except for data we are required to retain longer under applicable law. Records of paid transactions are kept for the period required by accounting law even after you delete your account; they are then no longer linked to your account but still contain the email address you used.

Data processed for analytics purposes is retained for a period appropriate to that purpose, but no longer than 24 months from the time it arose.

We share your personal data only to the extent necessary with the following processors and recipients: our database infrastructure provider (MongoDB) for storing app data; the PostHog tool for analyzing app usage (data processed on servers within the European Union); Sentry for reporting app errors and crashes; RevenueCat for managing Premium purchases and subscriptions; the Expo push notification service for delivering push notifications; Meta (Facebook) for measuring the effectiveness of our advertising, limited to the data described in section 2; the App Store (Apple) / Google Play for processing Premium payments and delivering notifications; and Apple and Google as sign-in providers (only if you choose to sign in with them). Apple, Google, and Meta act as independent data controllers under their own privacy policies.

We may also disclose your personal data to public authorities where required by law. We do not sell your personal data. The only data we send to an advertising company is the limited Meta event data described in section 2, used to measure the effectiveness of our advertising.

Some of the processors listed above may, to a limited extent, process data outside the European Economic Area, for example as part of the App Store / Google Play provider's infrastructure. In such cases, we ensure that the transfer takes place on the basis of standard contractual clauses approved by the European Commission or another equivalent legal instrument. This applies in particular to RevenueCat, Expo, and Meta, which may process data in the United States.

In connection with the processing of your personal data, you have the right to: access your personal data, correct inaccurate data, request erasure ("the right to be forgotten"), restrict processing, request data portability, object to processing based on legitimate interest, and withdraw consent where processing is based on consent (e.g. notifications or the iOS tracking permission).

You can delete your own study progress, XP, and streak at any time directly in the app, in Account → "Clear account history." You can also delete your entire user account, including registration data, directly in the app, in Account → "Delete account." Deletion is permanent. If you cannot use the app, contact us at chronotika@chronotika.com and we will delete the account for you.

If you believe we are processing your personal data in violation of applicable law, you have the right to lodge a complaint with the Office for Personal Data Protection (www.uoou.cz).

We store access credentials in a secured form (password hashing), and communication between the app and the server is encrypted (HTTPS). The app's authentication token is stored on the mobile device in secure storage, not in ordinary, unsecured memory.

Only individuals who genuinely need it to operate the app have access to personal data within our systems.

With your consent, the app may send study-streak reminders. These are scheduled locally on your device, and no data leaves it for that purpose. If you allow notifications, the app also registers your device's push token (and your app language) with our server so that we can send you occasional announcements, for example about a new course. We deliver them through the Expo push notification service and the operating system's own delivery service (Apple / Google), which receive the token and the message. You can turn notifications off at any time in your phone's settings.

Chronotika does not access your device's precise location (GPS) and does not track your movements. The only location information we process is the approximate location derived from your IP address, described in section 2.

The app is not intended for individuals under 15 years of age without the consent of a legal guardian. If we discover that we have unlawfully processed the personal data of a child under 15 without such consent, we will delete that data without undue delay.

We may update this policy from time to time, for example in connection with changes to the app's features or to applicable law. The current version is always available directly in the app.

If you have any questions or requests regarding the protection of personal data, please contact us at chronotika@chronotika.com.