
BookFere Translator is a mobile application developed by BookFere that enables fast translation of e-books into a bilingual format. Designed to help users expand their knowledge efficiently, it caters both to professionals seeking enhanced reading efficiency and to language learners aiming to improve their skills through original texts, providing a smooth and seamless reading experience.
Bilingual presentation serves as an effective tool for language acquisition. It allows readers to quickly grasp the content of foreign-language books, helping the brain map the native language to the target language, recognize grammatical and expressive patterns, and gradually reinforce vocabulary and sentence structures, laying a solid foundation for independent reading. When encountering unfamiliar words or complex sentences, the native-language reference provides contextual understanding, reducing reading frustration.
Previously, BookFere developed the Ebook Translator plugin for Calibre, which was limited to desktop use and therefore inconvenient for users who do not frequently work on a computer. With the new mobile application, e-book translation can now be performed with just a few taps on a smartphone. Kindle users can also conveniently push translated e-books to their devices for reading.
BookFere Translator aims to go beyond a simple translation tool, envisioning itself as a dedicated companion for foreign-language reading. Future plans include direct e-book reading with on-demand translation and AI-assisted support for understanding difficult words and sentences.

The initial release of BookFere Translator—the Minimum Viable Product (MVP)—supports EPUB format translation and integrates multiple translation engines, including Google Translate (Basic), Google Gemini, OpenAI ChatGPT, DeepSeek, DeepL API Free, and DeepL API Pro. Unlike the Calibre plugin, due to Google Play policies, the mobile app does not offer reverse-engineered free translation engines.
Additionally, BookFere Translator includes a testing engine, the Mock Translation Engine, which allows users to quickly test the translation workflow. This ensures layout and formatting can be verified before using paid translation engines, preventing unnecessary expenditure of paid quotas.
BookFere Translator is currently in closed testing. You can join the early-stage testing through the following steps:
- Ensure you have a Google account and that your smartphone or tablet can access Google Play.
- Visit the Google Group “BookFere Translator” and click Join group.
- On your device, use a web browser to click here to access Google Play and install the application.
BookFere Translator is continuously being refined. During the testing period, we welcome any feedback. You can leave a comment here, email us at [email protected]
, or submit feedback directly through the app.