Second Brain - Your AI memory companion that captures, connects & recalls

Second Brain is an AI memory companion for iOS that models how your mind actually works. Capture thoughts by text or voice. AI classifies each memory into three layers — instant, short-term, and long-term — extracts tags, and generates summaries. No folders, no manual sorting. Ask questions like "What did Sarah say last week?" and get answers from your own memories via semantic search. Weekly AI reflections find patterns in your thinking you missed. Free with limits, Pro at $4.99/mo.

Hey Product Hunt! 👋 I'm Liwei, a solo developer based in Finland. I built Second Brain because I kept losing ideas, forgetting promises, and never revisiting my own notes. The problem isn't capturing — it's recalling. I have hundreds of notes scattered across apps that I'll never look at again. I wanted something that actually thinks with me. The core idea is to mirror how human memory works: - Instant memories (fleeting thoughts) fade unless reinforced - Short-term memories (this week's plans) get processed and organized - Long-term memories (life experiences, core beliefs) persist and strengthen AI handles the classification automatically. You just dump your thoughts in — by typing or voice — and Second Brain figures out what it is, how it connects to your other memories, and surfaces it when relevant. A few technical choices I'm proud of: - Classification runs entirely on-device (zero API cost) - Explore queries are single-shot with hybrid recall, so token usage stays constant regardless of how many memories you have - Weekly reflections use Claude Sonnet for deeper analysis (Pro only) This is v1.1 — very early. I'm actively building based on user feedback. Tell me what resonates, what doesn't, and what you'd want to see next. Thank you for checking it out! 🙏

Second Brain - Your AI memory companion that captures, connects & recalls

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