ExtendedForms is an add-on for Google Forms, enhancing its capabilities for various applications. The platform includes features such as countdown timers, proctor settings for online exams, and integration with Google Classroom. It is designed to manage and monitor form responses, detect tab switching or full-screen status during exams, and automate scoring for classwork. ExtendedForms also offers customization options for forms, including branding, and allows exporting data to CSV for further analysis.