Cast Your Vote - Cast Your Vote is an app that allows you to set polls and a voting system and know the answer to your question.
Sli.do - Slido is the ultimate Q&A and polling platform for live and virtual meetings and events. It offers interactive Q&A, live polls and insights about your audience.
Pollie - Create polls and share them via your favourite tools
Poll Everywhere - Audience response system that uses mobile phones, twitter, and the web. Responses are displayed in real-time on gorgeous charts in PowerPoint, Keynote, or web browser.
poll.ly - your perfect partner to gather ideas and opinions in real time
Kahoot! - Kahoot! makes it easy to create, play and share fun learning games in minutes—for any subject, in any language, on any device.