Teachable - Create and sell beautiful online courses with the platform used by the best online entrepreneurs to sell $100m+ to over 4 million students worldwide.

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.

Clever - syncing between education applications for K-12 schools

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

Claroline - Claroline is a collaborative eLearning and eWorking platform.

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