Whitespace.
See who already built your idea — and the space they left open.

CLUSTER BRAIN-ORGANIZES-PERSONAL · 9 ENTRIES · EARLIEST ENTRY 2025-12-29

AI second-brain note apps

This cluster covers AI-assisted note-taking apps that aim to be a personal 'second brain' for organizing and retrieving information. The dated history is too thin to read a shape from, with only 2 dated entries months before the index start. The traction leaders, based on activity signal, are noteai, second-brain-lite, and solidify, all showing 0 stars.

Entry timeline

ENTRY TIMELINE

OCT 2025: 1DEC 2025: 1MAR 2026: 1AUG 2026: 1SEP 2026: 3OCT 2026: 2
OCT 2025OCT 2026

Each bar is the month a member carries, which is a creation date where the source published one and a crawl date otherwise. Nothing in the index was found before 11 August 2026, and coverage broadened sharply on 14–15 August, so a bar from then on reports how much we found that month, not how much was built; an earlier bar reports how far back a member's own source dated it — not how long we have been watching.

Members by activity

Activity signals, not revenue.

Build origin · 1 ai-built · 8 unlabelled

Operator · 7 hobby · 2 unlabelled

Two labels per entry, never collapsed into one: how it was built, and who stands behind it. Counted over the 9 listed below. Unlabelled means nothing has decided yet — not that the answer is small.

  1. 012nd-Mind0★22 days—hobbyChat-based personal memory app that stores notes, links and tasks and retrieves them by meaning, time, person, or category with transparent AI decisions.
  2. 02Nook0★15 days—hobbyOffline-first mobile and web app that serves as a personal second brain for notes and knowledge.
  3. 03second-brain0★15 days—hobbyPersonal productivity app for capturing notes and building a searchable second brain from scattered information.
  4. 04curio-engine0★23 days—hobbyMenu bar app that captures ideas and uses an AI model to enrich, link, and surface connections in a personal notes collection.
  5. 05noteai0★1 mo—hobbyAI-powered second-brain note-taking platform with semantic search, chat with notes, and auto-summarization for researchers and creators.
  6. 06second-brain-lite0★6 mostaleliveai-builthobbyAI-powered note-taking app that stores and organizes personal information to serve as a second brain.
  7. 07solidify0★9 mostalelivehobbyWeb app that organizes hierarchical notes and automates knowledge management as a personal second brain, using AI-assisted note processing.
  8. 08secondbrain-os0★1 yrabandonedliveAI-powered app that helps users capture, organize, and retrieve personal notes and information to boost productivity.
  9. 09Secondbrain0★unknownliveWeb app that captures, organizes, and retrieves personal notes and information as a second brain.

Ranked by traction, highest first, and paged 20 at a time — this is a window on the cluster, never the whole of it. Ties are broken by a stable id so a product cannot appear on two pages or fall between them. Browse every cluster.