Refined GitHub - Browser extension that makes GitHub cleaner & more powerful
Contributions for GitHub - Show your GitHub contributions graph on your iOS Devices
GitZip - Download or create a download link for a GitHub project folder/sub-folder or file.
GitHub Visualizer - Enter user/repo and see the project visually
GitHub Hovercard - GitHub Hovercard provides neat hovercards for GitHub.
GitHub Gardener - Daily, automated commits that turn your GitHub green