NearPod for Class/Workshop Polling – ProfHacker - Blogs - The Chronicle of Higher Education
Free Technology for Teachers: Nine Popular Student Response Tools Compared In One Chart
Free Technology for Teachers
Mentimeter - Turn opinions into tangible data, in real-time
Mentimeter: Polling service (audience response system) with value-packed free option, recommended by @wstagnaro
Kahoot! - Create new Kahoot!
Clickers
Free Technology for Teachers: Three Ideas for Using Plickers In the Classroom - Results of My First Trial
Free Technology for Teachers
Seven Good Student Response Systems That Work On All Devices
Free Technology for Teachers
10 Tools For Classroom Quizzes