Add-Ons are a great way to expand the features of Google Forms. Add-Ons are features created by third-party developers and approved by Google to be used with Forms.

Advance Summary by Awesome Tables: When you look at the responses in Google Forms they give you a basic graph of responses. This add-on gives you more detailed summary graphics for every question. This will also take short answer and paragraph responses and convert them to word clouds to see a summary of responses.

Choice Eliminator 2: This works best with dropdown questions but it allows students to eliminate choices as they are working through possible answers.

Timify.me: This uses an external site but connects with Google Form to put a timer on the assessment. Once the timer expires the students can not respond to the form any more. To make this work, the assessments must be email to the students.

Certify'em: This add-on emails a digital certificate to students when they earn a certain score on an assessment. As an instructor you can set the passing score that students need to receive their certificate.

Form Notifications: This add-on emails you when you receive a set number of form responses. You can set it for every time someone responds to groups of responses. This can notify you when that last student finally submits their assessment.