This document provides an overview of extending Gravity Forms through code examples. It begins with a demo of overloading Gravity Forms select fields with options from an external API. Code is presented to overload options and entire classes. Another demo shows sending form data to an external AR API. Additional code examples demonstrate adding custom validation, scripts, stylesheets and settings through the Add-On framework. The document concludes with information on Gravity Forms hooks and APIs for integrating with external services.