Other apps help you store. Second Brain helps you think. Capture a thought and let AI sort, connect, and resurface it — all private, all on your device.
The AI-powered journal that remembers everything. Capture thoughts by voice or text — AI organizes, connects, and recalls your memories so nothing is ever lost.
Second Brain models how your mind actually works. Every memory is classified into three layers — instant thoughts, short-term plans, and long-term knowledge — then linked, reflected on, and surfaced exactly when you need it.
CAPTURE IN SECONDS
Type a thought or press and hold to speak. AI automatically classifies each memory, extracts tags, and generates a summary. No folders. No manual sorting. Just capture and move on.
EXPLORE YOUR MEMORIES
Ask anything: "What did I decide about the project?" or "What did Sarah say last week?" AI searches across all your memories using meaning — not just keywords — and weaves relevant ones into a clear, contextualized answer.
PEOPLE MEMORY
Create cards for the people in your life. Track what they said, shared experiences, meeting notes, and to-dos. Never forget a birthday, a promise, or a conversation again.
WEEKLY REFLECTIONS
Every week, AI reviews your memories, finds recurring themes, spots growth areas, and offers a concrete suggestion — like a thoughtful friend reading your journal.
DISCOVER CONNECTIONS
AI builds a knowledge graph across your memories, revealing patterns and links you never noticed. Watch your ideas form constellations over time.
VOICE CAPTURE
Press and hold to speak. Real-time transcription fills your memory instantly. Switch between English and Chinese with one tap. Perfect for capturing thoughts on the go.
KEY FEATURES
- Three-layer memory system inspired by cognitive science
- AI classification, tagging, and summarization
- Semantic search — find memories by meaning
- Memory strength visualization with Ebbinghaus forgetting curve
- People cards with relationship tracking
- Daily, weekly, and monthly AI reflections
- Voice input with real-time transcription
- Theme clusters that reveal your thinking patterns
- Memory connection graph
- iCloud sync across devices
- Full data export (JSON + Markdown)
- Works offline — core features need no internet
- Privacy-first: your data stays on your device
SUBSCRIPTION
Second Brain is free to use with daily limits. Upgrade to Pro for:
- 20 memory explorations per day
- Deep weekly and monthly reflection reports
- Memory connection graph
- Theme discovery clusters
- Unlimited captures, people cards, and OCR
- iCloud sync and data export
Free 3-day trial available. Cancel anytime.
PRIVACY
Your memories are stored locally on your device. AI features use the Anthropic Claude API for processing — no other third party ever sees your data. Optional iCloud sync uses your personal Apple account. We never collect, store, or sell your information.
Terms of Use: https://smartkiitos.com/secondbrain/terms/
Privacy Policy: https://smartkiitos.com/secondbrain/privacy/
Ratings & Reviews
This app has not received enough ratings or reviews to display an overview.
This update is all about polish:
• Smoother upgrade screen — prices now load cleanly, no more flicker
• A friendly heads-up before your free trial ends, so a charge never catches you off guard
• Share cards make it easier for friends to discover Second Brain
• Performance and stability improvements under the hood
Keep capturing — we'll help you think.
Version 1.4.3
The developer, Liwei Xie, 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 Not Collected
The developer does not collect any data from this app.
Privacy practices may vary based, for example, on the features you use or your age. Learn More
The developer indicated that this app supports the following accessibility features. Learn More
Supported Features
Larger Text
Dark Interface
Differentiate Without Colour Alone
Information
Provider
Smart Kiitos Oy
Size
9.1 MB
Category
Productivity
Compatibility
Requires iOS 17.0 or later.
iPhone Requires iOS 17.0 or later.
Mac Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.