It's a great tool to do comprehension checks, especially for more complicated topics. I created a Kahoot for preterit and imperfect in Spanish, focusing on interpreting whether an action had been completed or not (based on a grammaticality judgment task I took as a grad student way back in the day). For example:
Anoche leía una novela.
Then students decide:
A. I finished the novel.
B. We don't know if I finished the novel or not.
(You could also add "C. I didn't finish the novel." to make it more interesting. For the curious, the answer is B; the use of the imperfect indicates that the action was in the past, but leaves the finality open-ended. In other words, when the imperfect is used, we don't know if the action/event was completed or not.)
Kahoots also are great for doing exam reviews, but I wanted my students to be able to use them on their own if they wanted, and not just during class. It's designed for use in a classroom, with the questions & answers projected on a screen and students responding from their devices, but they can use it individually with a few modifications. They have to create an account in Kahoot, and then they can access your activity in preview mode. One thing to note about preview mode is that it will not show up as an option if your browser window is too small, so if you're looking for it and it's not there, make your browser window bigger. I give students my Kahoot user name so they can look for my materials, and make sure to title them something obvious like "SPAN 1110 Exam 1 review."
In case it's helpful, I made a video for my students showing them how they can use Kahoots in preview mode for individual review.