To leave a class, you'll need to use the website. This is not currently available on the iOS or Android apps.
- Log in to your ClassDojo account via the website at https://teach.classdojo.com
- Find the class you want to leave and click on it to open the class
- Click on the "Settings" button on the right
- Click on "Edit Class"
- Click on the "Sharing" tab
- Find your name on the list and click on the "Leave Class" link next to your name