BookShelf

Privacy Policy

Last updated: July 1, 2026

This Privacy Policy explains how BookShelf ("we", "us", or "the app") collects, uses, and protects your information when you use the BookShelf iOS application. By using BookShelf, you agree to the practices described here.

Information We Collect

Account information. When you create an account, we collect your email address and, if you sign in with Google or Apple, the name and email associated with that account. Authentication is handled by Firebase Authentication (Google LLC).
Reading data. We store metadata about the books you import (title, author, reading progress) and your app preferences (languages, reading goal, reader settings) so we can sync your experience. Your book files themselves are stored locally on your device.
Saved words and lookups. When you tap a word to translate it, the word and its surrounding sentence are sent to our secure backend to generate the translation and dictionary information. Words you choose to save are stored with your account.
Purchase information. If you subscribe to BookShelf Pro, purchases are processed by Apple. We use RevenueCat to manage subscription status. We never see or store your payment card details.
Diagnostics. We may collect anonymized crash reports and basic usage diagnostics to keep the app reliable.

How We Use AI and Translation Services

When you look up a word, the word and its sentence context are processed on our servers and forwarded to Google Cloud Translation (for translations) and Google Gemini (for definitions, phonetics, and example sentences). These requests are made server-side through our secure infrastructure — no AI service keys are stored in the app, and requests are not linked to your identity beyond what is necessary to deliver the result to you. We do not send your books or any content you have not explicitly tapped to translate.

How We Use Your Information

To provide the core features of the app: reading, word translation, vocabulary saving, and syncing across sessions.
To manage your account and subscription status.
To maintain, debug, and improve the app.

We do not sell your personal data, and we do not use your data for third-party advertising.

Where Your Data Is Stored

Account data, saved words, and reading metadata are stored with Google Firebase (Firestore) on Google Cloud infrastructure. Book files and your local word cache are stored only on your device. Service providers we rely on (Google Firebase, Google Cloud, RevenueCat, Apple) process data in accordance with their own privacy policies.

Data Retention & Account Deletion

Your data is retained while your account is active. You can delete your account at any time from Settings → Delete Account inside the app. Deleting your account permanently removes your account information, saved words, and reading data from our systems. Locally stored files can be removed by deleting the app.

Children's Privacy

BookShelf is not directed at children under 13, and we do not knowingly collect personal information from children under 13. If you believe a child has provided us personal information, please contact us and we will delete it.

Your Rights

Depending on your location, you may have rights to access, correct, export, or delete your personal data. You can exercise most of these directly in the app (Settings), or by contacting us at the email below.

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 above.

Contact Us

If you have any questions about this Privacy Policy, contact us at:
bookshelf.support@gmail.com