Kahoot is a really quick and easy way to add some interaction into your class. It supports the creation of multiple choice style questions and your students use their mobile devices or laptops to respond.
Kahoot is free to use, and, at the time of publishing, did not limit the number of participants you use it with.
To set up your own Kahoot quiz, go to https://create.kahoot.it
Direct students to https://kahoot.it to play!
Kahoot is super easy to set up and use, but if you want to see it in action, take a look at the video below: