GrobPaint: Somewhere Between MS Paint and Paint.net. Multiplatform by Default

GrobPaint is a lightweight, multiplatform image editor positioned between MS Paint and Paint.NET, filling the gap for macOS users where Paint.NET is unavailable. Built with vanilla JavaScript and a small Python/pywebview backend, it offers layers, 16 blend modes, selection tools, sprite sheet support, and a native .gbp project format (ZIP-based), all without frameworks or build steps. The app runs as a native window via pywebview or falls back to a browser, and was built with significant help from Claude by Anthropic.