Kahoot (www.kahoot.com) is a gamified website that runs off of a web browser. It is great for engaging students and collecting diagnostic and formative assessment data. It can be for summative data, however is not recommended.
Ways you can use it in the classroom:
Below are a variety of videos outlining how to use Kahoot in the classroom.
Discovering Kahoot that are already made to play with your class.
If you duplicate them you can edit them to tailor them more to your learning outcomes!
Creating a Kahoot to play with your class.
The best part: Playing Kahoot!
Kids will actually cheer when they play this. They might beg you to play another round....just beware it might wear off the novelty of it.