I have used Kahoot with some level of success in German. Either as a vocabulary review (pretty easy) to quick reading comprehension (quite difficult). I like it because I can write my own to target specific skills or content, or I can adapt one somebody else has created.
Kahoot is a good tool to use when checking for understanding with students. I have used it as a review tool before a test or quiz. Students like the competition aspect as well as the learning. Students are gamers and competitors and like to be first. It is a way to see how students who may not answer questions in class are comprehending the topic. Small prizes to the winners adds to the challenge in students giving a correct answer rather than just clicking on one.