FREE

Free

$0 forever

No credit card required

Get Started Free
  • Read & annotate your books
  • Built-in EPUB reader
  • Spaced repetition reminders
  • $1 signup credit to try AI features
  • Pay-as-you-go AI processing
  • Device-only storage

What does content generation cost?

Credits are consumed when you generate learning content. Costs vary slightly by chapter length.

Feature Typical Cost What you get
Chapter Summary $0.01 – $0.03 Comprehensive chapter-by-chapter breakdown
Chapter Overview $0.005 – $0.01 Key themes and learning objectives
Audio Lecture Free Engaging lecture-style narration
Audio Readout Free Direct summary narration
Flashcard Set $0.005 – $0.02 Key terms with definitions and examples
Challenge Questions $0.005 – $0.02 Comprehension quizzes with feedback
Key Terms $0.005 – $0.01 Glossary extraction with definitions
Concept Map $0.005 – $0.01 Visual knowledge graph
Translation $0.01 – $0.03 Translate to any of 70+ languages
Ask a Question Free for Pro · $0.001 – $0.005 Per message, context-aware answers

💡 A typical 300-page book costs $0.50–$1.50 to fully process. Audio narration is always free — powered by our self-hosted AI voice engine.

Add credits anytime

Top up your balance in any amount. Credits never expire.

Need more credits? Top up your wallet anytime from the app. Credits never expire — use them at your own pace.

Frequently Asked Questions

Never. Buy credits when you need them, use them whenever you want. We know readers have irregular reading patterns.

Free lets you read and annotate your books, set spaced repetition reminders, and try AI features with your $1 signup credit. Pro adds 10 GB cloud storage with cross-device sync, $3/month in AI funds, and unlimited AI chat. You can upgrade or downgrade anytime.

Yes. Cancel your subscription anytime. You'll keep access until the end of your billing period, and all previously generated content remains accessible.

We believe you should only pay for what you use. Pro subscribers get $3/month in AI funds included — enough to process 2–4 books. Need more? Top up your wallet anytime. Free users can try AI with their $1 signup credit and add funds as they go.

A 300-page non-fiction book typically costs $0.50–$1.50 to fully process — that includes summaries, flashcards, audio lectures, challenges, key terms, and concept maps for every chapter. Shorter books cost less.