About OpenMark

OpenMark is built by Ryan McDonald — an indie developer making native apps for Mac and iOS.

I built OpenMark because I wanted a fast, native Mac app for opening and reading markdown files — and nothing that existed felt right. Every option was either an Electron app that took seconds to launch, a full knowledge-management tool that wanted me to import everything into a vault, or a code editor with markdown support bolted on as an afterthought.

OpenMark is the opposite of all of that. It's a SwiftUI app built from scratch for macOS Tahoe and iOS 18. It opens any .md file directly — no import step, no vault, no project. Double-click a file, see it rendered. Toggle to code view to edit. That's the whole idea.

It renders Mermaid diagrams natively, supports LaTeX math with KaTeX, and handles tables, code blocks, and every standard markdown extension. Version 1.2 added writing modes (Focus, Typewriter, Zen), four editor themes, image paste, and a companion iOS app — all as a Universal Purchase for $9.99.

No subscription. No account. No tracking. Your files stay on your devices.