Mark is a calm Mac notes app for markdown files that already live in a folder you share with someone else — on OneDrive, iCloud Drive or in a git repo. Point Mark at that folder and you get a clean sidebar, file list and editor on top of your existing files. The files on disk stay the source of truth: properties in YAML frontmatter, links as [[wikilinks]], nothing locked into a proprietary database, so the same folder keeps working in Obsidian, Finder or Claude Code.
