CodePen Software

JSitor is an online tool for testing and showcasing user-created and collaboration HTML, CSS, JavaScript and NodeJS snippets.

HTCSJS is an online HTML, CSS and JavaScript coding tool. It functions on mobile (unlike JSFiddle), and allows any* external resources. It also allows pasting on iOS, unlike many others.
http://shhnowisnottheti.me/demo/

*varies b/c it uses data URLs.