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.
Loomio - Loomio helps groups of people make decisions together, online.
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.
PollUnit - Create and customize public or anonymous votings, surveys, free tables, idea collections or audio, video and photo contests.
Glisser - Glisser makes presentations interactive – it takes regular PowerPoint, Keynote or PDF slide decks and pushes them out live to audience mobile devices. Your audience can then interact with the presenter with via polls, Q&A, voting and much more.
Mentimeter - a web-based polling tool for workshops, conferences & events