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.
Mentimeter - a web-based polling tool for workshops, conferences & events
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.
PollUnit - Create and customize public or anonymous votings, surveys, free tables, idea collections or audio, video and photo contests.
Kahoot! - Kahoot! makes it easy to create, play and share fun learning games in minutes—for any subject, in any language, on any device.