An exquisite list of awesome secrets.

• Astral – Organize Your GitHub Stars With Ease.
• DevSpace – Stay up to date with what's happening now on GitHub.
• Gitify – GitHub Notifications on your menu bar.
• Gitter – Provides free public chat rooms for open source repositories on GitHub.

• gitsome - A supercharged Git/GitHub command line interface (CLI).
• Friction – A tool to get rid of common sources of contributor friction.
• Ghizmo – The missing command line for GitHub.
• Git-stats – Local git statistics including GitHub-like contributions calendars.
• GitBar – Open Soure GitHub contribution stats in your MacOSX Menu.
• GitFame – Generates awesome stats from git-blame.
• GitHub Changelog Generator – Automatically generate change log from your tags, issues, labels and pull requests on GitHub.
• GitHub Cheat Sheet – A list of cool features of Git and GitHub.
• GitHub Contributors Table – Create a nice table of your contributors.
• GitHub Template Guidelines – Guidelines for creating template files for a GitHub project.
• Hub – Makes git better with GitHub.

• git.io – URL shortener for GitHub.
• GitHub-awards – Discover your ranking on GitHub.
• GitHubarchive [repository] – Record the public GitHub timeline, archive it, and make it easily accessible for further analysis.
• githut [repository] – Visualization of data from GitHub archive.
• issuestats [repository] – Analyze and compare how long it takes for GitHub issues to be closed.
• octoboard [repository] – GitHub activity dashboard.
• octodex – Octocats. Octocats everywhere.
• open source card [repository] – The Open Source Report Card.
• popularconvention [repository] – Analyzing code convention from GitHub commits.
• GitHub README Analyzer – Algorithmically improve your GitHub README.

• GitHub Avatars [chrome] - Display avatars in GitHub news feed.
• GitHub Awesome Autocomplete [chrome] [firefox] – Add instant search capabilities to GitHub search box.
• GitHub Categoric [chrome] – Categorize your mixed GitHub notifications.
• GitHub Hovercard [chrome] [firefox] - Neat user/repo/issue hovercard for GitHub.
• GitHub Isometric Contributions [chrome] [safari] – Render an isometric pixel art version of your GitHub contribution graph.
• GitHub Linker [chrome] – Link dependencies in a package or bower file to their GitHub page.
• GitHub Octotree [chrome] [safari] [firefox] [opera] – Display GitHub code in tree format.
• GitHub Selfies [chrome] – Add selfies to your pull requests and comments on GitHub.
• GitHub Stars Tagger [chrome] – Add tags to your starred repositories directly on GitHub.

You can see more on GitHub Browser Extensions.

• GitHub Contributions Generator – Generates a repository which being pushed into your GitHub account creates a nice contributions calendar.
• GitHub Hall of Fame [repository] – Hall of Fame for spectacular things on GitHub.
• GitHub Top Users [repository][spanish version] – GitHub top-1000 generation script.