GitHub Search is an Omnibox extension designed for the Chrome platform. It allows users to conveniently search repositories on github.com directly from the address bar by typing 'github' followed by a space. This tool enhances the browsing experience for developers and GitHub users by providing quick access to repository searches.

With GitHub Search, users can streamline their workflow by eliminating the need to navigate to the GitHub website manually for searching repositories. By simply utilizing the Omnibox feature, searching for specific repositories becomes more efficient and seamless. This free add-on by 8columns falls under the Browsers category, specifically as an Add-ons & Tools subcategory.