Anki - Anki is a program which makes remembering things easy. Because it's a lot more efficient than traditional study methods, you can either greatly decrease your time spent studying, or greatly increase the amount you learn.

Outgrow - Enabling marketers boost conversion with interactive, beautiful & viral quizzes/calculators.

LimeSurvey - LimeSurvey: the Online-Umfrage Tool - Open-Source Suryeys

doopoll - Create live, instant, editable polls effortlessly

Quizlet - Quizlet allows you to review and create flashcards for a variety of subjects, such as math and reading.

1World Online - 1World's Platform consists of applications like polls, quizzes, surveys, and debates to boost engagement and revenue opportunities.