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

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

VocApp.com is a vocabulary improvement software platform.

Memrise is a Language learning Platform with a website and iOS and Android Apps.

Cram is an online platform to create and share online flashcards.

zuknow is a social flashcard app.