Lexirion — Privacy Policy

Last updated: 10 October 2026

Lexirion is an e-book reader for Android. It is developed and published by ArTYug (Artem Yugay), the developer named on the app's Google Play listing, and distributed through Google Play. This policy explains what data the app handles, where that data goes, and what it never does.

Short version

• Lexirion has no accounts of its own and no analytics or advertising SDKs.
• Your books, reading positions, bookmarks and notes stay on your device — unless you turn on the optional backup to your own Google Drive. That backup holds no book files, and to make it the app asks Google only for permission to manage the files it creates itself; it does not learn your name or email address.
• The developer runs no server of their own and cannot see what you read or ask.
• Network requests go only to the public catalogues you browse, any catalogue address you add yourself, your own Google Drive if you turn the backup on, and — only when you ask a question about a book — to Google's Gemini: with your own API key, or, for a few free questions a day, through the developer's Google Firebase project.

Data stored on your device

None of this is transmitted to the developer. Uninstalling the app removes all of it from the device.

Android's own backup

This is the backup Android makes by itself, separate from the one the app can make at your request (section 4 below). If Android backup is enabled on your device, your reading progress, bookmarks, notes and settings may be included in your own Google Drive backup, under your Google account and subject to Google's terms. Book files, cover images, your Gemini API key and catalogue passwords are explicitly excluded from cloud backup. Book files are included in a direct device-to-device transfer when you set up a new phone; the API key and catalogue passwords are excluded from that as well and must be entered again.

Files you open

When you add a book, Android's system picker gives the app access to that one file only; when you add a folder of books, to that one folder and the folders inside it. For a folder, the app asks Android to keep that access, for reading only, so that books you put into it later are added the next time the app starts. Such folders are listed in Settings under Folders with books, and Stop following gives the access back; the list stays on your device and is left out of backups and device transfers. EPUB, PDF and CBZ files are opened where they are, and the app keeps read-only access to that one file so the book opens again later; books in other formats are converted and kept in the app's own private storage. Removing a book from the shelf gives that access back. The app does not scan, index or read anything else on your device. Lexirion requests no storage, location, camera, microphone or contacts permissions — nothing that can reach personal data. For itself the app declares INTERNET; FOREGROUND_SERVICE and FOREGROUND_SERVICE_MEDIA_PLAYBACK, so reading aloud continues when you switch to another app; POST_NOTIFICATIONS, for the notification with the pause button and for the evening reminder about your daily reading goal, if you turn it on; and RECEIVE_BOOT_COMPLETED, so that this reminder is set again after the phone restarts. The libraries it is built on add ACCESS_NETWORK_STATE, to tell whether the device is online, WAKE_LOCK, so reading aloud keeps playing when the screen turns off, and a signature-level permission of the app's own that no other app can hold. On Android 13 and newer, Android asks you about notifications when you first start reading aloud or turn on the evening reminder; if you decline, reading aloud still works, just without the notification, and the reminder stays off. All the others are granted automatically, and none of them opens access to anything personal.

Reading aloud

When you use Listen, the app hands the text to be spoken to the text-to-speech engine installed on your device. For a PDF that does not name its own language, the app first hands a short sample of its text, at most 1000 characters, to Android's language detector — a service of the device's system — so that the right voice is chosen. Lexirion itself sends none of this over the network. Both the speech engine and the language detector are parts of your device's system, supplied by its maker or by Google, and they handle the text under their own terms.

Data sent over the network

1. Book catalogues

When you use the Classics tab, the app contacts these public services directly from your device:

• Gutendex (gutendex.com) and Project Gutenberg (gutenberg.org, gutenberg.pglaf.org) — to search the catalogue, show covers and download books.
• Wikisource (ru.wikisource.org, ws-export.wmcloud.org) — to search and download books.

These requests contain your search terms and the book you chose, plus the technical information any web request carries, such as your IP address and the app's User-Agent string. Those services are operated by third parties under their own privacy policies. No identifier of you or your device is added by Lexirion. If you never open the Classics tab, no such request is made.

2. Your own OPDS catalogues (optional, none added by default)

Settings has an optional Custom catalogues section where you can add the address of any OPDS catalogue yourself — a library, a Calibre server, anything that speaks the format. None are added by default.

• Only https:// addresses are accepted.
• Before saving, the app makes one request to that address to confirm it opens and is a real OPDS catalogue.
• Once added, browsing or searching it works exactly like Gutendex or Wikisource above: your search terms and the book you choose go directly from your device to that address, plus the same technical information any web request carries.
• The address is not known to the developer in advance — you choose it, and the app does not suggest or bundle any third-party OPDS servers.
• If the catalogue needs a username and password, you enter them when adding it. They are stored only on your device, encrypted with a key held in the Android Keystore, are excluded from backups and from device-to-device transfer, and are sent only to that catalogue's own address — the same scheme, host and port — over HTTPS. The developer never receives them. Removing the catalogue erases them, and so does uninstalling the app or clearing its storage.
• Remove a catalogue in Settings at any time to stop any request to it.

3. Ask about a passage (optional; nothing is sent until you ask)

The reader has an optional Ask action: on selected text, or, from the bottom panel, about the story so far. Opening the Ask sheet sends nothing. A request is made only when you choose one of the ready questions or send your own, and it reaches Google's Gemini in one of two ways:

• With your own Google Gemini API key, entered in Settings or in the Ask sheet: the request goes from your device directly to Google's Gemini API, authenticated with your key.
• Without a key, a limited number of questions a day is free (20 at the time of writing): the same request goes to Gemini through Firebase AI Logic, a Google service, in the developer's Firebase project and at the developer's expense. How many of today's free questions you have used is counted on your device only.

Either way, this is what the request contains:

• The request itself: the selected passage (at most 2000 characters); a little of the text just before it (at most 1500 characters); the book's title and author, the title of the current chapter and how far into the book you are; the language your device is set to, so the answer comes in it; and the questions and answers already shown in that sheet, so that a follow-up question makes sense.
• Who is this?, What led up to this? and the first question about the story so far send, instead of the text just before the passage, the text of the current chapter from its start to your reading position (at most 12 000 characters) — never anything past where you are, and never other chapters.
• The request goes to Google, not to the developer. With your own key, Google's handling of it is governed by the Gemini API terms and Google's privacy policy for the account that issued the key. Without a key, Google processes it for the developer under the same terms as a paid service: Google states there that it does not use such requests or answers to improve its products and keeps them for a limited time only to detect abuse. The developer does not log, store or read the passages, questions or answers.
• In a PDF, on Android 15 and newer, there are no chapters and no text selection: Ask is opened from the bottom panel, and instead of a chapter it sends the text of the pages up to and including the one you are on — at most 12 000 characters, reaching back at most 40 pages, and never a later page. A PDF you opened with a password, and a PDF whose author has locked copying of its text, is never sent at all: there Ask says so and makes no request.
• Nothing else about you is sent: not the book file, not your library, not your identity.
• Without a key, three more things happen, all of them only when you ask. The first time, Google's Firebase software in the app creates a random Firebase installation ID; it identifies this installation of the app — not you, not your device, and it is not an advertising identifier — and it is sent to Google's Firebase services along with your questions. The app asks Firebase Remote Config for two settings: whether the free questions are currently on and how many a day are allowed. And the app asks Google Play (Play Integrity, through Firebase App Check) to confirm that the request comes from a genuine copy of Lexirion on a genuine device; that confirmation is attached to the request. It is there to keep scripts from spending the free questions. Clearing the app's storage or uninstalling it erases the installation ID from your device, and Google deletes it on its side once it is no longer in use.
• Answers are generated by an AI model and can be wrong. They stay in the sheet until you close it and are not stored. Report this answer opens a draft email to the developer with the passage and the answer; nothing leaves the device unless you send it.

If you never ask a question, none of this happens: the app makes no request to Google and no installation ID exists. With your own key in place, questions go directly to Gemini and the developer's Firebase project is not contacted at all.

The Definition action on a selected word first hands the word to a dictionary app on your device. Only if there is none does it offer to ask Gemini instead: then the word, at most 100 characters, is sent in the same way as a passage — with your key or as one of the free questions — and only when you tap Define in that sheet.

Translate, Definition and Open in another app in the Ask sheet can hand the selected text to another app installed on your device, chosen by you or by Android. That app handles it under its own privacy policy; handing it over sends nothing over the network from Lexirion.

4. Backup to your own Google Drive (optional; off until you turn it on)

Settings has an optional Backup in Google Drive. The first time you turn it on, Google's own account sheet opens: you choose a Google account and allow Lexirion to see and manage only the files it creates itself in that account's Drive (Google calls this permission drive.file). The app does not receive your name, your email address or your profile picture, and it cannot see anything else you keep in Drive. Google remembers that you allowed this, so turning the backup on again later may not ask a second time.

• What the backup holds. For each book: its title, author and series, the collections it is in, the dates you added, opened and finished it, and your reading place; the identifier the book carries or the app worked out from its contents, by which the book is recognised when you add its file again, and, for a book downloaded from a catalogue, its address there; your bookmarks, highlights and notes, each with the passage of the book it marks; your reading statistics; and the covers you chose yourself. Book files are not in it, and neither are your Gemini API key, your catalogue passwords or the app's settings.
• Where it goes. From your device straight to Google Drive (www.googleapis.com), as one file you can see there, named Lexirion backup with the model of the device and the date. The developer runs no server and never receives the file. In Drive it is kept under your Google account and Google's terms, like any other file of yours.
• When. Once when you turn the backup on; whenever you tap Back up now; and after that by itself, at most once a day — only if the library has changed, only on a network that is not metered, such as Wi-Fi, and not while the battery is low.
• What the file is marked with. The model of the device, and a random ID the app invents for this installation, so that it finds its own backup again and never writes over one made by another installation. The ID says nothing about you or the device. It is kept on your device and with the file in your Drive, and nowhere else.
• Restoring. Restore from a backup lists the Lexirion backups in your Drive — only files the app created — and downloads the one you choose to this device. What it holds is added to the library here; it is sent nowhere.
• Stopping. Turn off backup stops all of this. The file already in your Drive stays there until you delete it in Drive yourself. You can also take the app's access back at any time in your Google Account, in the list of third-party apps and services.

If you never turn the backup on, the app makes no request to Google Drive.

What is never sent

Lexirion does not transmit your library contents, the books you read, your reading positions, bookmarks, notes, or any device or advertising identifier to the developer. Nor to anyone else, with one exception that is yours to make: the backup in your own Google Drive (section 4), which carries the list of your books, your reading positions, bookmarks and notes — never the book files — and exists only if you turn it on. The app can have two identifiers, both random and both of this installation rather than of you or the device: the Firebase installation ID described in section 3, which exists only if you asked a question without your own key, and the backup's ID described in section 4, which exists only if you turned the backup on. There is no telemetry and no crash-reporting service in the app.

If the app crashes, it writes the technical details — app version, device model, Android version and the error trace — to a file in its own private storage, and offers to send them the next time you open Settings. Nothing leaves the device unless you tap that: the report opens as a draft in your own mail app, where you can read the whole text and decide whether to send it. If you do not, it stays on the device until the next crash overwrites it.

Children

Lexirion is not directed at children under 13 and collects no personal information from anyone. The catalogues it browses contain works of classic literature intended for a general audience; the app does not filter their content.

Your choices

• Delete a book in the app to remove its file, cover, bookmarks and notes.
• Clear the Gemini API key field in Settings to remove the key from the device.
• Add your own Gemini API key to keep your questions away from the developer's Firebase project altogether, or simply do not ask without one.
• Remove a custom catalogue in Settings to erase its address and, if you entered them, its username and password from the device.
• Turn off the backup in Settings to stop it; delete the backup file in your Google Drive to erase it; take the app's access to Drive back in your Google Account.
• Uninstall the app, or use Android's Clear storage, to erase everything it holds on the device. A backup in your Drive is not touched by that — it is yours to delete.
• The developer holds no data about you. If you asked without your own key, Google keeps the random installation ID in the developer's Firebase project until it falls out of use; it is not linked to your name, account or device, and you can write to the address below if you want to know more.

Changes

If this policy changes, the updated version will be published at this address with a new date at the top.

Contact

Questions about this policy, or reports about an AI-generated answer, can be sent to artyug.official@gmail.com.