Last updated: 6 November 2026
This policy explains what personal data the Biblion app handles, why, and the choices you have.
Federico Marchetti, an individual based in Turin, Italy, is the controller of your personal data. Contact: biblionbiblionbiblionbiblion@gmail.com.
Account: your email address, your name if your sign-in provider shares it, and sign-in details from Google or Apple. We use these to create and secure your account. Legal basis: contract.
Subscription: your plan and subscription status, from Google Play, the App Store and RevenueCat. We use these to give you what you paid for. We never see your card details. Legal basis: contract.
Reading data: your library, reading progress, bookmarks and settings, if you use Premium cloud sync. We use these to sync and back up your reading between devices. Without cloud sync, your books stay on your phone. Legal basis: contract.
Text for AI features: text you ask us to translate, explain or read aloud. We send it to an AI provider and return the result. Legal basis: contract; for books from your own files, your consent.
AI usage: how often you use AI features. We use this to apply plan limits and control costs. Legal basis: contract and legitimate interest.
App usage events: we use these to understand which features people use. They are sent only if you allow it. Legal basis: consent.
Error reports and technical logs: account id, device platform, system and app version. We use these to find and fix faults. Legal basis: legitimate interest.
When you translate, look up or listen to a passage, that text is sent to our AI providers through OpenRouter. For books from your own files, the app asks for your permission the first time. Those files may contain personal information, so please choose carefully what you send.
So that the same request doesn't have to be repeated, translations and audio are saved in a cache shared between users. The cache holds the text and its result, without your name or account.
We use these providers to run Biblion, and only for that purpose:
Supabase: account and database, hosted in the EU (Paris).
Microsoft Azure: the API and book storage, hosted in the EU (West Europe).
RevenueCat: subscription management. It receives your Biblion account id and purchase details.
Google Play and the App Store: payment and sign-in, under their own privacy policies.
OpenRouter and the AI model providers it connects to: AI text and speech.
PostHog: error reports, and usage analytics if you allow them, hosted in the EU.
We don't sell your personal data, and we don't use it for advertising.
Our main servers are in the EU. Some providers process data in other countries, including the United States. Where data leaves the European Economic Area and EU law applies, we aim to use appropriate safeguards, such as contractual protections, as the law requires.
Account data: until you delete your account. Deletion takes effect after a 30-day grace period, in which you can cancel it.
Technical logs: deleted after 90 days, or with your account.
Usage statistics: daily totals are kept for about 400 days.
Shared AI cache: kept after you leave, because it is not linked to you.
Purchase records: kept by the stores and RevenueCat, and as long as the law requires for tax and accounting.
Backups: copies held by our providers can last a little longer, until the backups rotate out.
Books stored only on your phone are not affected by deleting your account. Deleting your account does not cancel your subscription: cancel it in Google Play or the App Store too.
If you are in the EU, you can ask for access to your data, correction, deletion, a copy to take elsewhere, and limits on how it is used. You can object to processing based on legitimate interest, and withdraw consent at any time. You can also complain to your national data protection authority; in Italy, this is the Garante per la protezione dei dati personali. To use any of these rights, write to biblionbiblionbiblionbiblion@gmail.com. You can delete your account yourself in the app.
Biblion is not intended for children under 14. If you believe a child has given us personal data, please contact us and we will delete it.
If this policy changes in a way that matters, we will tell you in the app before it applies.