Socrative
Socrative is a free, web-based "Student Response" tool. It allows faculty to create quizzes (using multiple choice, true/false and short answer questions) and polls that they can show in class. The students can access and take the quiz from a computer or phone without needing a login to the Socrative site. They receive immediate feedback that the faculty member can also see, allowing them to determine if the students are 'getting it.'