elevio hub - For continuous user education
Commit Together by Github - Now add co-authors to your commits
List.community - Easy way to browse curated lists on GitHub
Commit Print - Posters of your git history
GitKraken - The intuitive, fast, and beautiful cross-platform Git client.
gitbird - So, I don't always remember to tweet what I do, but commit my code often, and what do users love more than your product?