Last updated: June 24, 2026
Lexifolio (“the App”) is developed by Cengiz Oger. This privacy policy explains what data the App collects, how it is used, and your choices.
Lexifolio is designed with privacy in mind. All your library data stays on your device. The App has no analytics, no tracking, no advertising, and no user accounts.
All of the following data is stored locally on your device and is never uploaded to any server:
This data is stored in the App’s private sandbox on your device.
If you choose to use the Cloud API summarization option, your API key is stored securely in the iOS Keychain with device-only protection. Each AI provider (OpenAI, Google Gemini, or a custom provider) has its own Keychain entry. Your key is never shared with anyone other than the AI provider you selected when generating summaries.
The App makes network requests only in three specific, user-initiated scenarios:
When you scan a barcode or enter an ISBN, the App sends the ISBN number to Open Library (a project of the Internet Archive) to retrieve book metadata (title, author, cover image). No personal data is sent — only the ISBN.
If you select “Cloud API” as your summary provider, the App sends the book’s extracted text, along with the book’s title and author, to the AI provider you select (such as OpenAI or Google Gemini) to generate a summary. For long books, the text is sent in sections and the summaries are combined. You can choose which provider and model to use in Settings. You can also configure a custom OpenAI-compatible endpoint. This is entirely optional. You can use the on-device Apple Intelligence summarization instead, which processes text locally on your device with no network requests.
When you tap “Look Up Online” for a dictionary word, the App sends the word to Wiktionary (a project of the Wikimedia Foundation) to retrieve a definition. No personal data is sent — only the word itself. This is a fallback for devices without Apple Intelligence (on-device AI definitions).
The App uses Apple’s on-device FoundationModels framework for:
These features run entirely on your device using Apple Intelligence. No text is sent to any server.
The App uses Apple’s Translation framework to translate saved dictionary words based on your configured language pairs (e.g., English → German). You can set up to 5 language pairs in the app. Translations are processed by the system Translation service on your device — no text is sent to any server.
The App requests camera access solely for scanning book barcodes (ISBN/EAN). The camera feed is processed locally to detect barcodes. No images or video are stored or transmitted.
The App accesses PDF and EPUB files you select through the system file picker or from monitored folders. Files are accessed using iOS security-scoped bookmarks. The App does not access files you have not explicitly selected.
You can export your dictionary, highlights, reading positions, sessions, monitored folder names, and ISBN-scanned books (with covers) as a .lexifolio backup file. This file is saved to a location you choose (e.g., Files app, iCloud Drive). Lexifolio never uploads backups to any server — the file stays wherever you save it.
All App data is stored locally on your device. To delete all data, simply delete the App. You can also delete individual books, dictionary entries, annotations, and reading history from within the App.
The App does not knowingly collect any personal information from children.
If this policy is updated, the changes will be posted on this page with an updated date.
If you have questions about this privacy policy, please contact:
Cengiz Oger Email: lexifolio.app@gmail.com