Kahoot! turns assessment into a game that all students enjoy and it also provides real-time feedback to help teachers assess students' needs and mastery levels.
Kahoot! now has a new Ghost Mode that allows students the opportunity to compete against themselves. They can play the same Kahoot! quiz over again in an attempt to beat their former score.
Another way that you can use Kahoot! is by allowing students to create their own quizzes. This can cut down on time that you, the teacher, spend creating the Kahoot! quizzes. Start by creating a Google Doc and allow the students to collaborate on the document adding questions. You can then review the questions to select which questions need to be used in your assessment. This also gives students ownership over the activity.
Check out Kahoot! at www.getkahoot.com