Obsidian second brain: turns brain dumps into linked notes, keeps daily notes and reviews, answers from your vault with links; never edits without your yes.
For litigation firms: spots billable work that actually happened, like confirmed appearances and signed drafts, and turns it into fee notes and invoices.
Keeps a personal second-brain wiki in a git repo: files your chats, notes, links and decisions as dated, sourced pages, flags conflicts and tidies weekly.