Google Analytics is a free web analytics service that tracks and reports website traffic.
jQuery CDN is a way to include jQuery in your website without actually downloading and keeping it your website's folder.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
UIKit is the framework used for developing iOS applications.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.