Hanzi mobile app

A while ago I wrote this little program for my mobile phone, to help memorize Chinese characters, or Hanzi (汉字). I published it today on hanzi.marcboon.com.
The application shows a virtual stack of three-sided cards, which can be flipped through in random order. The top of the cards shows one or more Chinese characters, representing a word or phrase, and the  idea is to try to remember the pinyin and English translation. If forgotten, you can refresh your memory by pressing the Up/Down keys to reveal the pinyin and/or English translation (the other two "sides" of the card). Pressing the Next button will show another card at random. Additional navigation is provided to view the cards in a fixed order (Forward and Back).
The program can alternatively be used to train the writing of Chinese characters, by selecting pinyin or English as the first view of a new card. The latter also trains your knowledge of Chinese vocabulary. The included vocabulary follows the lessons in my Chinese textbooks, and can be selected per lesson, or in any combination of lessons. In the first release, almost 500 characters and phrases are included, which is what I need to memorize for our upcoming mid-term test.
The program is written in Java, so it runs on any Java-enabled phone (virtually all phones, except the iPhone). However, the phone needs to be capable of showing Chinese characters (i.e. has a font for Simplified Chinese installed). This is generally not the case for phones sold outside East Asia. I bought a new phone here in China exactly for that reason (it has GPS too, so I will never get lost).
The software can be installed "over the air" by pointing your phone's browser to http://hanzi.marcboon.com/hanzi.jad, or by downloading that file and the jar file to your computer, and installing via bluetooth or USB using your phone's application installer or synchronization software. Total size is just 22kB, including data.