2sBrain:AI PDF Document Reader

Your Smart Local Second Brain

Free · Designed for iPad. Not verified for macOS.

Turn complex PDFs into actionable knowledge in seconds. AI-powered summaries, smart flashcards, and your personal second brain. Download 2sBrain today! 2sBrain — Your second brain, powered by AI. You read a lot but remember little? Documents, books, and notes scattered everywhere, slowly forgotten? 2sBrain turns them all into a personal knowledge base: AI reads for you, summarizes, connects knowledge across documents, and answers any question — based on exactly what you've added. ADD DOCUMENTS FROM ANY SOURCE • Scan books and paper documents with your camera — capture multiple pages in a row, AI analyzes instantly • Upload PDFs and many other file formats • Write notes in a rich text editor, insert images, one tap for AI analysis CHAT WITH YOUR OWN KNOWLEDGE BASE • Talk to the AI Assistant about your documents: summarize, explain, compare • Every answer comes with document sources and related concepts • Save valuable insights so your knowledge keeps growing and evolving over time KNOWLEDGE WIKI — CONNECTED KNOWLEDGE • AI extracts core concepts from each document • Concepts are cross-linked between documents into your personal knowledge graph • The more you add, the smarter your second brain becomes ANNOTATE & SIGN PDFS DIRECTLY • Highlight key passages and draw freely with a full pen kit: pencil, ink pen, marker, eraser, ruler, and custom colors • Add your signature to documents — sign contracts and forms right on your phone, no printing needed • Insert text notes anywhere on the page • Undo, erase, and edit freely; every change is saved right into the document • Feels like writing on real paper — but never gets lost LEARN LANGUAGES FROM WHAT YOU READ • Tap any word while reading for an instant definition, without leaving the page • Smart dictionary auto-detects the language: English, Chinese, Japanese, Korean, German, Vietnamese • Save words to vocabulary notebooks by topic • Review with flashcards — flip and swipe through your words SYNC ACROSS ALL YOUR DEVICES • Use it instantly without an account; your data stays safe on your device • Sign in to sync documents, notebooks, and chat history across devices 2sBrain is for students preparing for exams, engineers reading technical docs, language learners, and anyone who wants what they read to actually stick. Download 2sBrain for free — and start building your second brain today.

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This update makes getting documents into 2sBrain effortless — send or open PDFs straight from any app. IMPORT PDFS FROM ANYWHERE (NEW) • Share PDFs directly to 2sBrain from Files, Mail, Safari, Books and more — just tap Share and pick 2sBrain • "Open in 2sBrain" — open a document from any app and it lands right in your library • Import several files at once • Each file starts analyzing automatically — no extra steps Plus performance improvements and minor bug fixes for a smoother experience. If you find 2sBrain useful, please leave a review — it really motivates us to keep improving the app!

Version 1.0.3

The developer, Nguyen Nhu Vuong, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Linked to You

    The following data may be collected and linked to your identity:

    • Contact Info
    • User Content
    • Search History
    • Identifiers

Privacy practices may vary, for example, based on the features you use or your age. Learn More

Accessibility

The developer has not yet indicated which accessibility features this app supports. Learn More

Information

Seller
  • Nguyen Nhu Vuong
Size
  • 69.1 MB
Category
  • Productivity
Compatibility
Requires iOS 15.5 or later.
  • iPhone
    Requires iOS 15.5 or later.
  • iPad
    Requires iPadOS 15.5 or later.
  • iPod touch
    Requires iOS 15.5 or later.
  • Mac
    Requires macOS 12.4 or later and a Mac with Apple M1 chip or later.
  • Apple Vision
    Requires visionOS 1.0 or later.
Languages
English and 6 more
  • English, German, Japanese, Korean, Simplified Chinese, Traditional Chinese, Vietnamese
Age Rating
4+
Copyright
  • © 2026 Nguyen Nhu Vuong
  • Privacy Policy

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