Pingo - Optimize images for the web quickly 🖼️⚡

OnlineQuestions.org - OnlineQuestions.org is an online tool to ask and upvote questions during large lectures, classes...

Presentii - Imagine a tool that lets you capture audience interest in your presentation content as you present.

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.

SlideLizard - Powerpoint plug-in for live audience interaction

Kahoot! - Kahoot! makes it easy to create, play and share fun learning games in minutes—for any subject, in any language, on any device.