I built a 15MB desktop app that does one thing: renders markdown files beautifully and watches them for changes.
There are hundreds of markdown editors. Almost zero dedicated readers. When Claude Code or Cursor writes a design doc to disk, I don't want to edit — I just want to read it. VS Code's preview splits your workspace in half, browser renderers don't watch files, and Obsidian wants a vault. I just needed a separate window with beautifully rendered markdown that updates live.
Tauri (Rust + system WebView) instead of Electron keeps it under 15MB. Renders LaTeX, Mermaid diagrams, and syntax-highlighted code blocks. File watching via Rust's notify crate with debouncing. Fully offline, no accounts, no telemetry.
Free version has all core features. Paid adds tabs, themes, export.
Interactive demo: https://app.supademo.com/demo/cml7hp8pl6yyfzsad2v0ei2mn