Episteme Reader

A modern, offline‑first, privacy‑focused document & e‑book reader for Android, built with Kotlin and Jetpack Compose.

    

Overview

Episteme Reader is an offline-first reader for documents and e‑books on Android. It focuses on a clean and customizable reading experience.

Note: This is the Open Source (OSS) edition of Episteme Reader. The Google Play version is built from this core and may include additional proprietary features.

Features

Supported Formats

• Documents: PDF, DOCX
• E‑books: EPUB, MOBI, AZW3, FB2
• Comics: CBZ, CBR, CB7
• Text: MD, TXT, HTML

Reading Experience

• Themes (PDF & EPUB): Light, Dark, Sepia, OLED, Auto (system) and custom
• PDF Modes: Vertical scroll and paginated view
• EPUB Modes: WebView-based vertical scrolling and custom paginated engine
• Custom Fonts: Import user-provided fonts (.ttf, .otf)
• Typography: Adjustable font size, line spacing, and margins

Annotations (PDF)

• Ink Annotations: Pen, Highlighter, Eraser
• Text Annotations: Place notes anywhere, with system or custom fonts

Library & OPDS

• Library: Built-in organization and quick access to your files
• OPDS Support: Browse, search, and add books from OPDS 1.x/2.0 catalogs, with optional authentication

Accessibility & Utilities

• Text-to-Speech (TTS): Read documents aloud using the system TTS engine
• Offline‑first: Core features work fully offline; no analytics or tracking

Architecture

• UI: 100% Jetpack Compose (Material 3)
• Pattern: MVVM with Unidirectional Data Flow
• Database: Room (SQLite) for metadata and annotations
• PDF Engine: pdfium-android (Native PDFium bindings)
• EPUB Engine: WebView for vertical mode; custom renderer for paginated mode
• MOBI/AZW3: Custom JNI bindings to libmobi
• OPDS: Lightweight feed parsing and downloading (on-device)

Building from Source

1. Clone the repository:

   git clone https://github.com/Aryan-Raj3112/episteme.git
   cd episteme
   

2. Build:

   • Open in Android Studio and run the ossDebug variant, or
   • Build from the command line:

     ./gradlew assembleOssDebug
     

   The APK will be generated at:

   app/build/outputs/apk/oss/debug/Episteme-oss-v{version}-oss-debug.apk
   

Open Source Libraries

Powered by the Android OSS ecosystem:

• Core & UI: AndroidX, Jetpack Compose, Kotlinx Serialization
• Document Engines: PdfiumAndroidKt (PDF), libmobi (MOBI/AZW3), Google WOFF2 (fonts)
• Parsers: Jsoup (HTML/EPUB), Flexmark (Markdown)
• Media & Image Loading: Coil, Media3 (ExoPlayer)
• Utilities: Room (Database), Timber (Logging)

Contributors

• CCerrer — Testing & QA

License

Licensed under the GNU Affero General Public License v3.0 (AGPL‑3.0). See the LICENSE file.

Support the Project

Help make Episteme Reader even better.

• ❤️ Sponsor on GitHub
• ⭐ Star the repository to help visibility
• 🐞 Report bugs or request features via GitHub Issues
• 💬 Share feedback in Discussions (ideas/UX): Discussions
• ✍️ Leave a review on the Google Play Store
• 📣 Tell a friend!