MD Preview App — macOS Markdown Viewer Skill by ara.so — Daily 2026 Skills collection. A fast, native macOS app (AppKit + WKWebView) for reading files. No Electron, no browser tab. Features include a document outline sidebar, Mermaid diagram rendering, KaTeX math, Quick Look extension, in-document search, and one-click "Open With" for popular editors. --- Installation Pre-built (recommended) Download the signed and notarized DMG from the Releases page and drag to . Build from source Requirements: macOS 15+, Xcode with Swift 6.0, Apple Silicon or Intel. --- Project Layout --- Key Dependencies…