Flat UI Pro Tutorial: How To Use jQuery to Add Functionality to a Custom Mailbox Flat UI Pro Tutorial: How To Use jQuery to Add Functionality to a Custom Mailbox CodingDavid East • January 16, 2014 • 1 minute READ Now that you have gone through a series of tutorials with David East to create a custom mail app, he is back in this lesson to show you how to add jQuery functionality to it. The videos