More Software and Audio Study Resources

For Android and iPhone, a lot of Nihongo learning apps are available.
Meanwhile, for Windows Phone, here are some free apps as posted in this blog
by the creator of NihongoUp, that great Nihongo learning app for the iPhone, Android,
desktop, and Windows Phone.

• Tango Master
• Eng-Jap Dictionary
• NihongoUp

Update: For Windows CE mobile phones, here's a dictionary that you can use - .cab installer (but haven't tried): http://www.ookii.org/software/pocketdictionary/

Look for other Windows and Linux Japanese software at Jim Breen's Japanese page: http://www.csse.monash.edu.au/~jwb/japanese.html

This dictionary might work too on Windows CE: http://www.cs.arizona.edu/projects/japan/JavaDict/download/index.html

Next, for more advanced learners, these podcasts on learnjapanesepod.com may help. 
The link leads to a top ten list of Japanese cheat sheets - numbers, etc, for aiding memorization.
Also, last in the list is TaeKim's guide to Japanese grammar.

This grammar guide (TaeKim's) is highly recommended.
You may download the pdf version, however, be warned that there are
a lot of Kanji without any furigana. Better to start with the html version since the tooltip
contains the hiragana readings.

NHK also has 50 10-minute Japanese lessons here.
The vocabulary introduced is perfect for JLPT N5 and N4.