Commit Together by Github - Now add co-authors to your commits
Refined GitHub - Browser extension that makes GitHub cleaner & more powerful
GitHub Marketplace - Tools to build on and improve your workflow
GitZip - Download or create a download link for a GitHub project folder/sub-folder or file.
GitHub Hovercard - GitHub Hovercard provides neat hovercards for GitHub.
Board for Github - A webview based GitHub project app with native features