All Japanese All The Time
http://www.alljapaneseallthetime.com/ AJATT suggests to fully immerse
yourself in the Japanese language. However, it mainly supports doing
things that you like doing, but with the Japanese language (e.g. playing
video games, reading books, watching movies, etc...).
AJATT seems to be "make Spaced Repetition cards from content that
you normally consume".
A primary concept is "Fun gets done."