Leaf Privacy Policy

Last updated: October 17, 2026

This Privacy Policy explains how we collect, use, disclose, and safeguard your information when you use the Leaf application for iOS and Android (the "Application"). The Application is provided by Color Hub, operated by Luka Katsadze, a sole proprietor based in Tbilisi, Georgia ("we", "us", or "our"). Please read this Policy carefully. If you do not agree with it, please do not use the Application.

1. Data Controller

For the purposes of the EU General Data Protection Regulation (EU) 2016/679 ("EU GDPR"), the UK GDPR, and similar data protection laws, the data controller for personal data processed in connection with the Application is Luka Katsadze (Color Hub), Tbilisi, Georgia. You can contact us about this Policy or to exercise your rights at support@colorhub.online.

2. Information We Collect

2.1 Information You Provide

When you create an account or use the Application, we collect the following personal data:

  • Email address: to create your account, authenticate sign-in, and send service communications.
  • User ID: a unique identifier (a Firebase Authentication UID) generated for your account. You may also use the Application without signing in (an anonymous account). In that case only this identifier exists until you link a sign-in method.
  • Display name and username: the name received from a sign-in provider (Sign in with Apple, Google Sign-In) or set by you, and your public username. A username is generated for you automatically, and you can replace it with one you choose.
  • Profile image and profile banner: if you upload them or if an image is received from a sign-in provider.
  • Your library: the books you track, with their reading status, ratings, page or percentage progress, start and finish dates, re-reads, favorites, personal notes, custom titles and custom covers; your reading sessions and reading timer history; your reading goals; and your lists.
  • Comments and reviews: what you write about books, including ratings in reviews and any images you attach, and your likes.
  • Social graph: the people you follow and who follow you, and any reports or blocks you submit.
  • AI assistant conversations: the messages and photos you send to the assistant and its replies (see Section 4).
  • Imported data: if you import from another service (for example a Goodreads CSV export or a Read More backup), the books, statuses, ratings, dates and shelves contained in the file you choose. The file is read on your device. Only the resulting library entries are stored, together with the rows we could not match to a book, so that they can be resolved later.
  • E-reader sync: if you pair an e-reader with the Application, the reading sessions it reports (book file, duration, position) and the paired device record.
  • Ideas and feedback: feature ideas you suggest on the in-app ideas board and the ideas you vote for.
  • Support correspondence: the contents of any messages you send us by email. A support email composed from the Application is pre-filled with your app version, device model, operating system, language and user ID, so that we can help you. You can remove these before sending.

2.2 Information Collected Automatically

When you use the Application, we and our service providers automatically collect:

  • Internet Protocol (IP) address;
  • device information: operating system and version, device model, language, time zone, and app instance identifiers;
  • usage information: screens visited, features used, and the time and duration of use;
  • crash, error and performance data (for example stack traces and the device state at the moment of an error);
  • a push notification token, if you allow notifications;
  • subscription and purchase status (entitlement information, never full payment card data).

The Application does not collect precise (GPS-level) location data. When you scan a book's barcode, the camera image is processed on your device; only the decoded ISBN is sent to look the book up.

3. Your Library and Social Features

Leaf is a personal reading tracker. The content you save is stored so that we can deliver it back to you across your devices. We never sell your library, and we use your notes, custom titles and custom covers only to operate the Application for you.

3.1 Your public profile

Leaf gives every account a profile page. Your profile is open by default, which means any signed-in user of the Application can see:

  • your display name, username, profile image, banner, the date you joined, and your follower and following counts;
  • the books in your library, which of them are favorites, and when you added them;
  • statistics computed from your library, such as how many books you have in each status, the distribution of your ratings, and your genres;
  • a calendar of your reading activity by day and by month;
  • the lists you publish, the people you follow and who follow you, and your comments and reviews.

Your personal notes, custom titles, custom covers, reading sessions and AI conversations are never shown on your profile. You can close your profile at any time in Settings → Profile → Privacy. Closing it removes your library, statistics, activity calendar and lists from other users' view. Your display name, username and profile image stay visible so that people can still find you. A user you have blocked cannot see your profile.

3.2 Following and activity

Following is one-sided and does not need approval. When you add, start, finish, rate or re-read a book, write a comment, or follow someone, the Application creates an activity event that the people who follow you can see in their feed. Each event carries the book's title and cover. You can turn off sharing your book activity in the social settings; turning it off deletes those events. Without a linked sign-in method you can read profiles and comments, but you cannot follow anyone, comment, or report.

3.3 Comments and reviews

Comments and reviews you post on a book are visible to every signed-in user, together with your display name, username and profile image. If you or another user asks to translate a comment, its text is sent to Google Gemini (Section 6) to produce the translation.

3.4 Images you upload

Your profile image, banner, comment images and custom covers are stored at unguessable addresses. Anyone who has such an address, for example because they saw the image in the Application, can open the image.

3.5 Book catalog

Information about books (titles, authors, covers, descriptions, series, bestseller lists) is not personal data. It is fetched from external catalog providers (Section 6) through our servers. Providers receive your search text or an ISBN, but not your identity or your library. Cover images are loaded directly from the providers' image servers, which therefore see your IP address. When you add a book, its title, author, cover, year, genres and ISBN are saved in your library so that it keeps working if the provider changes.

4. The AI Assistant

The Application includes an optional AI assistant that can answer questions, recommend books, and add or update books in your library at your request. Before you first use it, the Application asks for your consent. You can turn the assistant off at any time in Settings → AI assistant.

  • What is sent: your messages, any photos you attach, and the library data the assistant looks up to answer you (for example titles, statuses, ratings, progress, dates and notes). This is sent to Google's Gemini models through Google Cloud Vertex AI.
  • Your control: in the AI assistant settings you can stop the assistant from reading your library, your progress, or your ratings. When a category is off, the assistant cannot access it.
  • Storage: your conversations and attached photos are stored in your account so that you can return to them on any device. You can delete a single conversation, or all conversations and photos, from the Application at any time.
  • Limits: we keep a counter of your requests to apply the free and subscription limits. It contains no message content.

AI replies can be inaccurate. Do not rely on them for decisions that matter.

5. How We Use Your Information and Legal Bases

We process your personal data only where we have a lawful basis to do so under Article 6 GDPR:

  • To create and maintain your account: performance of a contract (Art. 6(1)(b)).
  • To store, sync, and deliver your library to your devices: performance of a contract.
  • To operate your public profile, follows, activity feed, comments and reviews: performance of a contract. You control what is shared through the profile privacy and social settings.
  • To run the AI assistant: your consent (Art. 6(1)(a)), which you can withdraw at any time in the Application's settings.
  • To send notifications: your consent, given through the system permission prompt and the in-app notification settings, which you can withdraw at any time.
  • To process payments and manage subscriptions: performance of a contract; legal obligation (tax, accounting).
  • To provide customer support: performance of a contract; legitimate interest in responding to user requests (Art. 6(1)(f)).
  • To review reports of objectionable content or behaviour and enforce our Terms: legitimate interest in keeping the Application safe; legal obligation where applicable.
  • To detect, prevent, and address fraud, abuse, or security incidents: legitimate interest.
  • To analyse usage, fix errors and improve the Application: legitimate interest.
  • To send service-related communications (account, security, billing, policy changes): performance of a contract; legal obligation.
  • To comply with legal obligations and respond to lawful requests: legal obligation (Art. 6(1)(c)).

We do not use your data for advertising, we do not track you across other companies' apps or websites, and we do not engage in automated decision-making that produces legal or similarly significant effects on you.

6. Third-Party Service Providers

We use trusted third parties to operate the Application. Each provider acts as our processor (or, where it determines its own purposes, as an independent controller) and receives only what it needs for its purpose:

  • Google Firebase (Authentication, Firestore, Cloud Storage, Cloud Functions, Cloud Messaging, Analytics, Remote Config, App Check): account identifiers, library storage, uploaded images, push tokens, device and usage analytics.
  • Google Cloud Vertex AI (Gemini models): AI assistant messages, photos and the library data the assistant reads; texts of comments you ask to translate.
  • Apple and Google sign-in: authentication, if you choose to sign in with them.
  • RevenueCat: subscription state, purchase events, your account identifier, email address and display name.
  • Sentry: error, crash and performance reports, including your IP address and device context.
  • Book catalog providers: Open Library, Google Books, The New York Times Books API, Apple Books search, Wikidata and TheTVDB (for screen adaptations of books). They receive search queries and ISBNs from our servers, and image requests from your device.
  • Apple App Store and Google Play: payment processing and delivery of in-app purchases. We do not receive your full payment card number from them.

7. International Data Transfers

We are based in Georgia. Several of the service providers listed above are established in the United States or other countries outside the European Economic Area (EEA), the United Kingdom, or Switzerland. When personal data is transferred outside the EEA/UK, we rely on appropriate safeguards under Articles 44–49 GDPR, including the European Commission's adequacy decisions (including the EU–US Data Privacy Framework for certified US providers), the Standard Contractual Clauses and the UK International Data Transfer Addendum, and additional technical and organisational measures where required. You can request a copy of the relevant safeguards at support@colorhub.online.

8. Notifications

  • Reading reminders are scheduled on your device. Their settings stay on your device and are not sent to us.
  • New follower notifications are push notifications sent through Firebase Cloud Messaging. We store your device's push token in your account for this purpose and remove it when you sign out. You can turn these notifications off in the Application's notification settings or in your device settings.

9. Payments and Subscriptions

The Application offers optional auto-renewing subscriptions and one-time purchases that unlock premium features. Billing is processed by the Apple App Store or Google Play, and subscription state is managed through RevenueCat. We receive only the purchase and subscription status needed to deliver your entitlements. Subscriptions renew automatically at the end of each billing period unless cancelled at least 24 hours before the period ends. Cancellations, refunds, and trial terms are governed by the policies of the respective store.

10. Disclosure of Information

We do not sell or share your personal information, as those terms are defined under California law. We may disclose personal data only:

  • to other users, to the extent described in Section 3;
  • to our service providers (Section 6) acting on our behalf under appropriate contracts;
  • to comply with law, including subpoenas, court orders, or other valid legal process;
  • to protect rights and safety, where we believe in good faith that disclosure is necessary to investigate fraud or abuse, prevent harm, or protect our rights, property, or the safety of our users or the public;
  • in a corporate transaction such as a merger, acquisition, or asset sale, in which case we will require the recipient to honour this Policy;
  • with your consent, or at your direction.

11. Data Retention and Deletion

We keep personal data only for as long as needed for the purposes in this Policy:

  • Account data and everything you created (library, reading history, lists, profile, follows, activity, comments and reviews, images, AI conversations, ideas): for as long as your account exists.
  • Activity events: until you delete the underlying book, turn off sharing of your book activity, or delete your account, whichever comes first.
  • Reports of objectionable content or behaviour: up to 2 years, so that repeated reports can be assessed.
  • Purchase and subscription records: up to 7 years where required by tax and accounting laws.
  • Support correspondence: up to 3 years from the last interaction.
  • Crash and diagnostic data: typically up to 90 days.

Deleting your account. You can delete your account at any time in Settings → Profile → Delete account. Deleting your account permanently deletes your account and all the data associated with it, including your library, reading history, lists, profile, follows, activity, comments, reviews, uploaded images and AI conversations. This cannot be undone. Residual copies in backups are erased within 90 days. Records we are legally required to keep (such as purchase records) are retained only for the period the law requires. You can also ask us to delete your account by emailing support@colorhub.online.

12. Your Rights

12.1 Rights under EU/UK GDPR

If you are in the EEA, the UK, or Switzerland, you have the right to:

  • access your personal data and obtain a copy (Art. 15);
  • rectify inaccurate or incomplete data (Art. 16);
  • erase your data, the "right to be forgotten" (Art. 17);
  • restrict processing in certain circumstances (Art. 18);
  • receive your data in a portable, machine-readable format (Art. 20). The Application also lets you export your whole library as a JSON file at any time in Settings;
  • object to processing based on legitimate interests (Art. 21);
  • withdraw consent at any time, where processing is based on consent (Art. 7(3));
  • lodge a complaint with your local supervisory authority (Art. 77).

12.2 Rights under California law (CCPA/CPRA)

If you are a California resident, you have the right to know what personal information we have collected about you, its sources and purposes, and the categories of third parties we disclose it to; to request deletion and correction of your personal information; to opt out of the "sale" or "sharing" of personal information (we do neither); to limit the use of sensitive personal information; and not to be discriminated against for exercising these rights. You may designate an authorised agent to make a request on your behalf, subject to verification.

12.3 How to exercise your rights

Contact us at support@colorhub.online. We will respond within the time required by law (generally one month under the GDPR and 45 days under the CCPA, extendable where permitted). We may need to verify your identity before fulfilling a request.

13. Children's Privacy

The Application is not intended for children under 13, and we do not knowingly collect personal data from children under 13. In jurisdictions where the minimum age of digital consent under the GDPR is higher (for example 14 in Italy and Spain, 15 in France, 16 in Germany and the Netherlands), users below that age may use the Application only with the consent of a parent or legal guardian. If we learn that we have collected personal data from a child below the applicable age without such consent, we will delete it. If you believe this has happened, contact us at support@colorhub.online.

14. Security

We use reasonable technical and organisational measures to protect your information, including encryption in transit (TLS), encryption at rest by our cloud infrastructure providers, server-side access rules that limit each record to the people allowed to see it, and app attestation that rejects requests that do not come from a genuine copy of the Application. No method of transmission or storage is fully secure, however, and we cannot guarantee absolute security.

15. Data Breach Notification

If a personal data breach is likely to result in a risk to your rights and freedoms, we will notify the competent supervisory authority without undue delay and, where feasible, within 72 hours of becoming aware of it (Art. 33 GDPR). Where the breach is likely to result in a high risk, we will also notify affected users without undue delay (Art. 34 GDPR).

16. Consumer Right to Cancel

If you are a consumer in the EU or UK, unless an exception applies, you have a statutory right to cancel a purchase within 14 days without giving a reason. To cancel, send us a clear statement of your decision at support@colorhub.online before the period expires. For subscriptions, this right applies to the initial subscription and not to each automatic renewal. Refunds for in-app purchases are processed by Apple or Google under their policies.

17. Changes to this Policy

We may update this Privacy Policy from time to time. We will post the updated version on this page and update the "Last updated" date. For material changes, we will give additional notice (for example an in-app notice) and, where required by law, ask for your consent again.

18. Contact Us

For any questions or requests about this Privacy Policy or our processing of your personal data, contact us at support@colorhub.online. See also the Leaf Terms of Use.