JA Sensei - Complete suite to Learn Japanese !
Jisho - Powerful and easy-to-use online Japanese-English dictionary with words, kanji and example...
Akebi Japanese Dictionary - Offline Japanese-English kanji dictionary.
JWPce - JWPce is a free Japanese <--> English dictionary and word processor created by Glenn...
Anki - Anki is a program which makes remembering things easy. Because it's a lot more efficient than traditional study methods, you can either greatly decrease your time spent studying, or greatly increase the amount you learn.
RomajiDesu - RomajiDesu is a free online bi-directional Japanese-English dictionary, Kanji dictionary, Sentence analyzer and Japanese to Romaji/English translator, and Romaji to Hiragana/Katakana Converters for Japanese learners.