BookWidgets - BookWidgets is an excellent application that let you create engaging exercises in minutes and easily share a varied variety of beautiful and fun activities with your classroom and others.
Simple Poll - The easiest way to create polls in Slack
Padlet - Visual boards for organizing anything.
GitHub Polls - Polls for GitHub issues and readme
Socrative - Socrative helps teachers engage the class with educational activities to measure and visualize...
minipoll - Create simple shareable polls in seconds