First, it's a great option for a review game. You can write a quiz with various questions from a unit and have students play the Kahoot to see how prepared they are and to reinforce the concepts. As you can see in this video, students get very into it and are quite excited when they get the right answer - although a little less excited when they learn that they're still not on the leaderboard!
Here is an example of a Kahoot that I created as a review game for an Algebra class. Since it's public, anyone can play it! However, that means someone needs to be the "teacher" and run it. If you just want to play it by yourself, you'll need to be both the teacher and the student. For example, you can launch it from your computer and see what would be displayed on a projector screen but play as a student on a mobile device like your phone in order to answer the questions.
It's also a great way to poll your class. You could pose a question at the beginning of class and ask them which answer they think is correct. This can be a great warm-up. You could also take a poll at the end of class - perhaps asking students how well they believe they understand the lesson from that day.
Finally, I'm really excited about the prospect of having students create their own Kahoots for their classmates to participate in. You could assign topics to individual students or groups and then have them do the research and create quizzes. Not only would they need to learn the information, but they would have to design good questions and answer choices. These activities would allow students to be extremely active in their own learning!
I definitely intend to use Kahoot with my students this year. I think they're going to love it, and I'm confident that they'll learn quite a lot while having fun!
I hope you'll try making your own too. It's quick and easy, but if you're having trouble, just check out this page for answers to lots of potential questions. You'll also find some great tips on this blog.