There is a fantastic dictionary app for Mandarin called Pleco that includes a SRS-based flashcards feature as an in-app purchase (around $10-15 if I recall). T

There is a fantastic dictionary app for Mandarin called Pleco that includes a SRS-based flashcards feature as an in-app purchase (around $10-15 if I recall). The base dictionary itself is free. While of course you can just program your own cards into Anki or the like, being able to create new cards from dictionary definitions with one tap is very handy.