Commit Together by Github - Now add co-authors to your commits
Commit Print - Posters of your git history
GitHub Marketplace - Tools to build on and improve your workflow
Macarons - Macarons is your virtual watercooler for casual conversations with colleagues you rarely meet on the hallway.
Refined GitHub - Browser extension that makes GitHub cleaner & more powerful
Commits.io - Create a poster for your office using your code