I am able to choose from "Kahoots" that have been created by other teachers around the world, but more importantly, I can create my own to use just for our classroom.
Basically, I put together questions with multiple-choice answers, hopefully addressing a current standard or set of standards. When I launch the Kahoot!, students - armed with iPads - see the question and answer choices on the SMART Board. They answer individually on their iPads, and the results are tabulated in real time. Top five scores are displayed on the board, along with how many chose each possible answer.
Finally, it is possible to download the results with allows me to see which students picked each possible answer. Additionally, the download includes information about the speed at which each student answered.