JWPce - JWPce is a free Japanese <--> English dictionary and word processor created by Glenn...
Bilingua - Bilingua: your language exchange app & learning companion.
Obenkyo - Obenkyo is an app to help you learn Japanese on the Android Market
LingQ - Learn languages by immersing yourself in a world of interesting, authentic content!
zkanji - zkanji is a free and open-source study tool and dictionary of the Japanese language.
Mondly - Learn 33 languages in 500 bite-size lessons and 14 conversational modules.