EPUB & PDF Reader – GemReader

Gemperial

About this app

GemReader is an offline EPUB and PDF reader that saves everything you do inside a book — your form answers, highlights, notes, and flashcards. Built for people who read to learn, not just to finish.

No account. No cloud. No tracking. Your library is encrypted on your device.

YOUR FORM ANSWERS ARE SAVED
Most ebook readers throw away what you type. GemReader doesn't. Fill in a workbook exercise, close the book, come back a week later — your answers are exactly where you left them. Every text field, checkbox, dropdown, and radio button in an interactive EPUB is saved automatically.

HIGHLIGHT AND ANNOTATE
Highlight passages in six colors and attach a note to any highlight. Add standalone text notes, bookmarks, and notes pinned to images. Notes support Markdown. Tag anything you keep, name the highlight colors yourself, and see every highlight and note from your whole library in one searchable list.

STUDY TOOLS BUILT IN
Look up any word in the in-book dictionary without leaving the page. Turn your highlights into flashcards and drill them with the built-in spaced repetition review deck. Export annotations to Anki, or import your existing .apkg and .txt decks straight into the app.

FREE BOOKS TO START WITH
Browse Project Gutenberg, Standard Ebooks and other open catalogs from inside the app and download straight into your library. Add any OPDS catalog you trust. Downloads are encrypted on arrival, like every other book.

LISTEN TO YOUR BOOKS
A neural text-to-speech voice reads any book aloud, generated entirely on your device — no cloud, no account, and no connection needed once the voice is installed. Books that ship with their own chapter audio play that instead, with lock-screen playback controls.

PDF READER INCLUDED
Open PDFs alongside your EPUBs. Fixed-layout rendering, working links and form fields, pinch-to-zoom, full-text search, and dark mode.

ENCRYPTED LIBRARY
Your books are encrypted at rest with AES-GCM. No plaintext file ever touches disk. Lock individual collections behind their own key, and lock the whole app when you put it down. Your books stay yours.

BUILT FOR OFFLINE READING
Everything works with the network off. Nothing is uploaded, no account is required, and there is nothing to sign in to.

ORGANIZE A REAL LIBRARY
Grid and list views, nested collections with custom colors, cover art, full-text search across your library, table of contents, footnotes, image zoom, and reading history so you can jump back to where you were three chapters ago.

MADE COMFORTABLE TO READ
Light, dark, sepia, and high-contrast Ultra themes. Adjustable fonts, margins, and layout. Immersive full-screen reading. Downloadable font packs for CJK and non-Latin scripts. Tablet and split-screen support. Interface available in 15 languages: English, Spanish, Portuguese, Hindi, Indonesian, French, German, Russian, Arabic, Chinese, Japanese, Korean, Burmese, Khmer, and Amharic.

SHARE WITHOUT THE CLOUD
Gem Beam hands a book, or a whole collection, to the phone next to you over a private Wi-Fi link. One device shows a code, the other scans it, and the books cross directly — no internet, no account, nothing leaving the room. Highlights, notes, reading position and study progress travel with them. You can also export a book as an encrypted .gem pack, optionally as a scannable QR code, or turn a favorite passage into a shareable quote card image.

WHO IT'S FOR
• Students working through interactive textbooks, workbooks, and study guides
• Language learners who need a dictionary, flashcards, and audio in one place
• Researchers and professionals who annotate heavily and need it to stay put
• Anyone who wants a private, offline ebook reader with no account attached

GemReader reads standard EPUB and PDF files, including large EPUBs up to 200MB. Import from your device, share a file into the app, or download directly through the in-app browser.

What’s new

Fixes a crash that closed the app while the extra fonts were being unpacked, on Android 14 and newer. The unpacking runs as a background job the app was no longer allowed to start, and being refused took the app down with it. Nothing was lost, and any book open at the time reopens where you left it.