Backchannel Chat - Backchannel Chat is best in class discussion tool that is intended for teachers to streamline their class activities.
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.
NowComment - NowComment is a complete suite of collaboration tools, streamlining group discussion, annotation, and curation of texts, images, and videos.
Kahoot! - Kahoot! makes it easy to create, play and share fun learning games in minutes—for any subject, in any language, on any device.
Eduflow - Digital learning that actually teaches students something
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.