GitZip - Download or create a download link for a GitHub project folder/sub-folder or file.
GitKraken Glo Boards - Easily track tasks and issues from inside popular dev tools
Refined GitHub - Browser extension that makes GitHub cleaner & more powerful
GitHub Hovercard - GitHub Hovercard provides neat hovercards for GitHub.
GitHub Marketplace - Tools to build on and improve your workflow
Board for Github - A webview based GitHub project app with native features