What is PDF & EPUB Reader-Editor?
PDF & EPUB Reader-Editor is an Android application for reading and annotating digital documents without an internet connection. It handles both PDF and EPUB formats in a single app, eliminating the need to switch between different readers depending on file type. The reading experience is optimised for long sessions - adjustable fonts, three colour themes (white, sepia, night), and a clean interface that gets out of the way of the content.
Beyond reading, the app includes a full annotation layer. Users can highlight text in multiple colours, add margin notes, draw freehand annotations, and bookmark pages. All annotations are stored locally alongside the document and persist across sessions. The annotation layer works the same way across both PDF and EPUB formats.
The app includes a text-to-speech engine that reads documents aloud using the device's built-in TTS system. Users can control reading speed, pause and resume, and navigate by chapter while listening. This makes the app useful for accessibility purposes and for consuming long documents hands-free.
What it does
PDF and EPUB in one app
Opens and renders both PDF and EPUB formats natively. No format conversion required. Documents are rendered accurately with fonts, images, and layout preserved.
Three reading themes
White, sepia, and night (dark) themes with adjustable brightness. Font size, font family, line spacing, and margin width are all adjustable per document.
Highlight and annotate
Multi-colour text highlighting, margin notes, freehand drawing annotations, and sticky notes. All annotations are stored locally and visible on re-open.
Bookmarks and progress
Bookmark any page or location. The app remembers reading position across sessions so users always return to exactly where they left off.
Table of contents navigation
Tap the TOC to jump to any chapter or section instantly. Works for both PDF outlines and EPUB chapter structures.
Full-text search within documents
Search for any word or phrase within the open document. Results are listed with surrounding context and jump directly to each occurrence.
Text-to-speech reading
Reads the document aloud using the device TTS engine. Adjustable speed, pause/resume, and chapter-by-chapter navigation while listening.
How it's built
The app is built natively for Android using Java and Kotlin. PDF rendering uses a native PDF library integrated via JNI. EPUB parsing is handled by a custom Kotlin parser that interprets the EPUB container structure, spine, and content documents. Annotations are stored in a local SQLite database alongside document metadata. The text-to-speech feature uses the Android TextToSpeech API.