FlashTabs - Flashcards in your new tab screen
Machine Learning Flashcards - 300 digital flashcards
Brainscape - Find, create, and study SMART FLASHCARDS on any device. DOUBLE your learning speed using the most effective study system on the planet. Keep all your content in sync across Brainscape's website and your Android devices.
Fresh Cards - Flashcards that just work
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.
Flashcards.io - Free offline first flashcards maker