Tinycards is an educational and reference application developed by Duolingo. It uses flashcards to help users learn topics more effectively by engaging their memories with visuals and audio. The app helps users learn more than 500 topics, including science, math, language, music, and pop culture. Users can also create their own flashcard decks and share them with friends. Tinycards also provides users with access to a library of content created by educators and other users, featuring topics for all ages. Tinycards provides a fun and interactive way for users to learn and retain knowledge.
Open source and incredibly customizable. It is available on virtually all devices and has a very good spaced repetition algorithm.