Kahoot! - Kahoot! makes it easy to create, play and share fun learning games in minutes—for any subject, in any language, on any device.
Godot Engine - Feature-packed 2D and 3D open source game engine.
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.
GDevelop - GDevelop is an open-source game making software designed to be used by everyone.
Mentimeter - a web-based polling tool for workshops, conferences & events
Construct 2 - Scirra Construct is a 2D game development engine with a focus on building games visually.