GitZip - Download or create a download link for a GitHub project folder/sub-folder or file.
GitHub Metrics - Customize your profile with various plugins and metrics
Refined GitHub - Browser extension that makes GitHub cleaner & more powerful
GitHub Contributions - All your GitHub contributions in one image
GitHub Hovercard - GitHub Hovercard provides neat hovercards for GitHub.
Contributions for GitHub - Show your GitHub contributions graph on your iOS Devices