Riffle - Your Smart English Reading Companion
Riffle is a powerful tool designed to make reading English books more enjoyable and effective while helping you build your vocabulary naturally.

Key Features
* Smart Reading Experience
Read EPUB and PDF books with a clean, customizable interface
Adjustable font size, style, and themes including Dark Mode
Smooth page navigation with progress tracking
* Instant Translation & Learning
Tap any word or phrase for instant translation
Smart word form recognition (handles plurals, tenses, etc.)
Save words directly to your vocabulary list
View detailed word information from multiple online dictionaries
* Vocabulary Management
Build your personal vocabulary list while reading
Review words in context with original sentences
Track your learning progress
Organize and manage your word collection
* Scientific Recitation System
Smart spaced repetition system for efficient learning
Personalized review schedules
Progress tracking for each word
Context-based learning with original sentences
* Interactive Listening Practice
Listen to your vocabulary words with high-quality text-to-speech
Customize playback sequences:
Word pronunciation
Letter-by-letter spelling
Translation
Context sentences
Multiple playback ranges:
All vocabulary words
Current study list
Words due for review
* Sentence Collection
Save useful sentences while reading
Automatic translation
Original context preservation
Quick navigation back to source