Anki
Open Source
Anki is a spaced repetition flashcard program. Anki is the Japanese word for memorization.
Quizlet
Freemium
Quizlet makes simple learning tools that let you study anything.
Busuu
Freemium
Busuu is a social network for learning languages.
Ninchanese
Freemium
NinChanese is a story-based, interactive language application that teaches you to speak, read, write, and understand Chinese.
zuknow
Freemium
zuknow is a social flashcard app.
Babbel
Commercial
Babbel is a subscription-based language learning app and e-learning platform.
Duolingo
Free Personal
Duolingo is a freemium language-learning platform that includes a language-learning website and app.
AnkiApp
Commercial
AnkiApp is a flashcard app for iOS (iPhone + iPad), MacOS, and Android.
AnkiDroid
Open Source
Anki is a spaced repetition flashcard software.
VocApp.com
Free
VocApp.com is a vocabulary improvement software platform.
SuperMemo
Free Personal
SuperMemo is a learning method and software.
