Stories - Master complex materials through short daily stories.
Mochi - Write notes and flashcards with Markdown and study them with spaced repetition.
Glean.co - Personalized learning for educational video lessons
Harken - Flashcard app using smart repetition to improve your memory
Cloudbite - Bite-sized cloud learning with spaced repetition
SmartCards+ - Spaced Repetition Software for iOS. Modern, powerful and easy to use.