RealKana - Practice hiragana and katakana recognition by choosing which characters you want to practice and typing their romaji equivalents. Also available for iOS.
Nihongodict - free online Japanese-English dictionary
Renshuu - personalized vocabulary lessons, community discussion, and games
Kanji Project - Guide to kanji stroke order with animated .gifs from University of Michigan
Handwritten kanji recognition - Look up kanji by drawing them with the mouse
JapanReference - Japanese grammar guide
Jisho is a powerful Japanese-English dictionary. It lets you find words, kanji, example sentences and more quickly and easily.
Enter any Japanese text or English word in the search box and Jisho will search a myriad of data for you.
Transparent Language is a complete language-learning system for independent learners of over 110 languages, including Japanese. Transparent's Japanese for English Speakers course consists of 40 lessons including listening, speaking, reading, and writing practice.
NHK World Easy Japanese - "Easy Japanese" is a program of Japanese language lessons produced by Japan's public broadcaster, NHK WORLD RADIO JAPAN. You can learn basic grammar and useful expressions through lessons designed in audio-drama style. You can download audio and texts for the lessons free of charge.
Dr. Moku's Hiragana Mnemonics - Visual mnemonics to help remember the 46 hiragana and their sounds ($4.99) | Dr. Moku's Katakana Mnemonics - Visual mnemonics to help remember the 46 katakana and their sounds ($4.99) | Kana Quiz - Hiragana and katakana flashcards featuring vocabulary words (first three levels free, $.99 to unlock full version) |
LingoDeer - Interactive lessons and reviews in Japanese, Chinese, and Korean, designed by language teachers (free) | RealKana - Choose hiragana and katakana to practice and identify them by typing their romaji equivalent ($2.99) | Kanji Monster Defense - Kanji learning game where player must match kanji to their meanings to attack "demons" and save the princess. (free) |
Japanese - Japanese-English offline dictionary featuring over 160000 entries with 10000+ kanji and almost 60000 example sentences (free) | Handwriting Japanese Kanji - Practice writing and learn stroke order for hiragana, katakana, and kanji (free) | NHK Japanese Lessons - Audio dramas spoken by native Japanese speakers (free) | WordSearch Japanese - Japanese word search game (free) |
LingoDeer - Interactive lessons and reviews in Japanese, Chinese, and Korean, designed by language teachers (free) | Dr. Moku's Hiragana & Katakana - Visual mnemonics to help remember hiragana and katakana and their sounds. ($6.99 for both alphabets) | Kanji Monster Defense - Kanji learning game where player must match kanji to their meanings to attack "demons" and save the princess. (free) | Tae Kim's Guide to Learning Japanese - Lessons on hiragana, katakana, kanji, basic grammar, special expressions, and advanced topics. (free) |