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.
Eduflow - Digital learning that actually teaches students something
Padlet - Visual boards for organizing anything.
Flowlingo - Get fluent in a language through content immersion
Quizlet - Quizlet allows you to review and create flashcards for a variety of subjects, such as math and reading.
Kialo - Kialo is the platform for rational debate. Empowering reason through friendly and open discussions.