There are several places on the site that use custom icons. Even better, you can add icons yourself, by inserting the following code into just about any editable content area:

<span class="icon icon-name-here"></span>

 A full list of available icons can be found at http://mk033.monkpreview.com/_assets/fonts/icons/

(use your domain when your site is live, ex: https://mydomain.com/_assets/fonts/icons/)