I’ve been studying Japanese diligently at smart.fm. I study in Kana mode because that’s what I can do right now, Kanji mode would be impossibly slow. I’m in great luck that I had 100% on word recognition of JLPT3 and JLPT4 a month ago, so it helps speeding things up. Dictation is somewhat of a challenge because I didn’t practise any grammar yet.
What I really like is the game “Brainspeed”. 
I could play that game for hours on end.
Learning languages isn’t very difficult for me, math however… could be a challenge. lol. I also dislike my mother tongue, especially to write in. I’d be writing a sentence and then forgetting the Dutch word for something and the English is right there. Never ever have that the other way around.