IconRulesAgent – Customize macOS App Icons

It wires a simple but satisfying UX — drag-and-drop a .app into a 'Drop Your App Here' window and the app creates a rule folder, edits rule.conf, and applies default.icns/png automatically. The implementation leans on a filesystem watcher and menu‑bar controls (no Dock icon), which makes repeated theming and bulk updates trivial; it's not groundbreaking, but it's exactly the sort of small automation macOS tinkerers will love. The only real friction is that you build and run it in Xcode rather than a packaged release.