iWadi - Take online paid surveys. Help your favorite brands and earn money online with iWadi online survey panel. Sign up for free.

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.

SurveyLab - Professional online survey tool - best survey software for the best price - Satisfaction Surveys, NPS, Market Research, Online Survey Creation and real-time reports.

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

Survey Monkey - Create and publish online surveys in minutes, and view results graphically and in real time. SurveyMonkey provides free online questionnaire and survey software.

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