Here are some our (FREE) favorites!
Plickers- Print out free Plicker response cards from their website (it's better if you print them on cardstock rather than just paper). Install the free Plickers app on your mobile device. Students hold up the printed Plickers cards to respond to a multiple choice question (A,B,C, or D) and all you need to do is just wave your mobile device in front of the cards. It captures footage of them and immediately gathers results. It is awesome!
Kahoot- An awesome quiz show game that works on all kinds of devices! Teachers can make their free quizzes on getkahoot.com. After making your quiz, you can activate it. This will give a pin number so that students can join your quiz by visiting kahoot.it and typing in the pin number.
Poll Everywhere- A great way to poll your students! This website not only does multiple choice but also allows participants to text in responses. Create your poll and it will walk you through the process!