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

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.

Quizzes for Pages - Quizzes for Pages is an application to create and share quizzes on your Facebook Page.

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

Poll Everywhere - Audience response system that uses mobile phones, twitter, and the web. Responses are displayed in real-time on gorgeous charts in PowerPoint, Keynote, or web browser.

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