I have used Kahoot on almost every test to help them study. Since I teach elementary, sometimes I create a Kahoot based on the test so that they can become familiar with some of the test questions ahead of time.
I love Kahoot! The kids love to play the trivia games and set up teams to see who can beat the other. It is a great way to create a review game before assessments, or assess prior knowledge to a new topic.
I truly enjoyed using Kahoot in the classroom. It was always engaging and fun. I would have it on the screen between classes. When the tardy bell rang, students had to be ready to play. It was a great way to get started immediately!
I worked as an associate for some 5th grade classrooms that used Kahoot. It was used for studying new vocabulary and Social Studies facts. I observed that the students really enjoyed playing the game and I was able to play along with them as I wasn't the one who administered the quiz. They enjoyed competing with one another and I think it helped them learn and also relieve test anxiety. As I played along with them I thought was fun too. Since I'm transitioning into subbing next school year I can see myself using this tool to help the kids learn.
I love Kahoot. I found that it can be used as an entertaining way to study, or that I can individual assignment to students in Classroom. It is a great tool for assessing. With my older students, I did find that I have to use it sparingly. Almost all of the faculty discovered Kahoot at about the same time, so they were burned out with it right pretty quickly.
I have used Kahoot as well. My preference now is quizizz. Take a look and compare them. I like the ability you have to use it as homework, not just a live game in class. Both of them are very effective tools.
I have been using Kahoot this past year and really enjoy it with my first graders. I enjoyed seeing your other suggestion of quizizz. I have never used this site however I like the idea of not having to do it in real time and assigning it as homework or independent practice. I will explore this as an addition to Kahoot.
I've used Kahoot in the past and it is a lot of fun. It's a bit competitive and a lot of the "success" depends on how fast an answer is entered, so those that take a bit more time to process information will definitely be at a disadvantage.