While PollEverywhere can be simple, the deeper you dig the more features you’ll discover. At it’s heart, it’s a response system that’s intended to be used with mobile devices. You ask a question (open ended or multiple choice) and students can respond through text messaging.
If you want to try out the site, you can create a free poll right from their home page. Enter in your question(s), add the answers if it is to be multiple choice, and then click submit. You’ll be brought to a page that displays directions for how people can vote. The site is incredibly responsive, which is one reason it is so popular. As each answer arrives, the responses show up immediately on the screen. This can create dramatic tension as the bar graph displaying the answers swings back and forth with the incoming votes!