zkanji - zkanji is a free and open-source study tool and dictionary of the Japanese language.
Takoboto - Japanese dictionary & Japanese language learning tool.
Sumatora - Offline Japanese dictionary for Android
Rikaichamp - Look up Japanese words with the hover of a mouse.
Handy News Reader - Handy News Reader is a free no-ads RSS reader for reading offline contents from RSS feeds or web sites without RSS feeds.
rikaikun - Translate Japanese by hovering over words.