[alanX]

Kotoba.
It's a Japanese-English English-Japanese dictionary.

キングソフト辞書
(Kingsoft Dictionary)
Same thing as above.

産経新聞
Sankei Newspaper; A Japanese newspaper.

ShinKanji
An electronic Kanji dictionary.

今日の中吊り (Today's Advertisement)
This one is kind of hard to explain.
Basically you can view advertisements that are in trains, magazines, etc.
(Just kind of fun when you're bored.)

クーリエ-ジャポン
(Courrier Japon)
Basically a Japanese magazine.



I don't know of any apps that actually "teach" you Japanese. Not that I would recommend that anyways. These apps just help getting connected to Japan, and give some useful and helpful reading material.

I don't know your Japanese level, but if you can't read Japanese at all then 産経新聞, 今日の中吊り, and クーリエ-ジャポン are going to be useless to you.

EDIT: Also, all of these apps are totally free. You're welcome.