StudyArcade – you can download/sync everything with Anki, especially awesome when you’re going some where without internet. And its free which is great :)

Hot Radio Japan: Free, it has top 10 radios etc. Bad internet connection makes the app really annoying ,_,.

Tunein Radio Pro 0.79 euro, that’s like 0.99 dollars?. Lots of Japanese radio stations. What’s great about this is that “you can pause and rewind live radio just like your DVR”. It also shows which (japanese)song is playing, you have the option to record.