Kahoot is a great game-based classroom response system and students absolutely love it!!
How I use it in my Spanish classes: I use Kahoot to practice reading in the target language and learn new vocabulary. I usually write each question/description/definition of a word along with the answers/choices all in Spanish. Each student enters the game individually or in small groups entering a game specific code @ Kahoot.it. It is an engaging activity for students completly done in the target language!
To add some culture: There is an experimental feature in Kahoot that allows you to add a video to automatically play while waiting for students to join the game (See screenshot below!). To take advantage of this 1-2 minutes of downtime on my most recent Kahoot created game, I included a video tour of Barrio Gótico in Barcelona, Spain. It was a great way to expose students to one of the more famous neighborhoods of Spain, since we are currently studying how neighborhoods differ and how where you live affects daily choices/routines, and further maximize learning in the classroom!