Clickers as a classroom response system(CRS or feedback system).

Following are few videos which explains fairly well about the concept and application of clickers in classrooms >

A brief description of some approaches to using student response systems in a classroom: BY Russell James

Using Clickers in the College Classroom

(Created by the Center for Instructional Innovation and Assessment at Western Washington University:)

How to write great clicker questions: Faculty Workshop by University of Colorado Boulder, presented by Stephanie Chasteen

Clickers in Science Classroom

There are also some apps and platforms which enable online and distance clicker function.( Source educause.edu )

• ClassPager https://www.classpager.com/ (Mobile and Text)
• eClicker: http://www.eclicker.com/ (Mobile: iPhone and iPad)
• iClicker: http://www.iclicker.com/ (Clicker and Mobile)
• iPAL: http://www.compadre.org/ipal/webdocs/About.cfm NGLC grant funded (Mobile and Web)
• iReponse App: http://iresponseapp.com/ (Mobile: iPad, iPhone, iPod and Web)
• Lecture Tools: http://www.lecturetools.com/ (Mobile)
• PINGO: http://trypingo.com/ (Mobile)
• Poll Everywhere: http://www.polleverywhere.com/ (Mobile, Text and Web)
• Qwizdom: https://qwizdom.com/education (Clickers and Web)
• Socrative: http://www.socrative.com/ (Mobile and Web)
• Top Hat Monocle: http://www.tophatmonocle.com/ (Mobile and Web)
• Turning Technologies: http://www.turningtechnologies.com/ (Clicker, Mobile and Web)
• Ubiquitous Presenter: http://up.ucsd.edu/ (Mobile)
• UCLA Mobile Web Framework: https://oit.ucla.edu/mobile-web-strategy/mobile-web-framework(Mobile)