pre-commit - A slightly improved pre-commit hook for git
gitsome - Supercharged Git/Shell autocompleter w/ GitHub integration
GVfs - Git Virtual File System (by Microsoft)
Kite - Kite helps you write code faster by bringing the web's programming knowledge into your editor.
Git Flow - Git Flow is a very self-explanatory free software workflow for managing Git branches.
YOURLS - YOURLS is a website that contains all the tools you need to create and launch your very own URL shortener. URL shorteners like bitly or TinyURL are fine for public use, but they offer limited options in terms of URL customization.