Are you looking for a way to quickly assess students and get an idea if they comprehend a topic or not? Do you have a smartphone or tablet? There is a free app called plickers that is used on the computer and a portable device. Students have an assigned card with a graphic that is read by the device. It records responses immediately to do a check for understanding.
I really feel this is a simple and easy way to do a check for understanding in a class. The response is quick and immediate and the prep work isn't too intense. You start off making a question and determining the correct answer. Then you load the question into your plicker and share it with the students on the screen. Kids hold up a card that is assigned to them and the responses appear on your device and are stored on the web. I tested it with my class and it was so easy to use.
I can see this being used for not only a check for understanding or an exit ticket but also as a way to have kids to surveys. You can create 4 potential topics and ask the kids to vote. It's simple. I like how fast the responses come back to you and how easy it is to use. I would recommend giving it a shot. It's a great tool for the classroom.