Learning Japanese, or wish to start? Maemo port of a libre desktop program Kanatest can help you learn both katakana and hiragana characters.
Kanatest will test your knowledge by showing you kana characters and having you type in their romaji equivalents. At the end, your statistics will be shown, and later you can compare your older results with your new ones.
What makes it a really-really good piece of learning software are tons of helpful functions and features, like translations of the program to other languages, definable lessons together with many predefined ones, a complete character chart, test on either kata, hira or both, the aforementioned statistics, which can be shown in a nice graph or table, minor things, like font customization.
Kanatest can be fetched from Extras, there are no differences with the Devel or Testing versions, find it under Education section in a graphical package manager or simply run:
apt-get install kanatest
So, if you’re into learning Japanese, go check the app out. It will be worth it.