Made a simple form-builder demo for my work. Has sorting, almost every type of input, and works pretty well.
Could use a few more options for help text and drag-n-drop sorting.
Shows how AngularJS and CSS can play together for form validation. AngularJS port of this jQuery Password strength verification: http://www.webdesignerdepot.com/2012/01/password-strength-verification-with-jquery/