Kahoot! is an online-based quiz/survey thing [a la Socrative, Hands Up, etc], but this one forces the participants to be focused on the front of the room [i.e. they aren’t looking down at their device reading the questions because all they have to do is click the color or shape].
It has Surveys, Quizzes, and Discussions. Questions can be timed from 5 to 120 seconds, and you have an option for it to automatically move on to the next question [when time runs out OR everyone has answered] OR it will wait for you to click.
You can also add graphics to accompany a question.
Kahoot works with just about anything with a web browser and internet access – i.e. cell phones, Kindles, iPads.