Anki is a spaced repetition flashcard program. Anki is the Japanese word for memorization.

Anki is a spaced repetition flashcard software.

zuknow is a social flashcard app.

VocApp.com is a vocabulary improvement software platform.

AnkiApp is a flashcard app for iOS (iPhone + iPad), MacOS, and Android.

Mnemosyne is a free flash-card tool which optimizes your learning process.

Quizlet makes simple learning tools that let you study anything.