GitDuck - GitDuck is the easiest way to explain your code to other developers. Show how you code and record videos linked to your source code.
Codewell.cc - Improve your HTML and CSS skills by practicing on real world design templates.
CodeShare.io - Realtime code sharing for developers
Good Code - Free front end coding challenges
CodeTogether - Live share IDEs and coding sessions. See changes in real time.
One Degree - The Human Search Engine