Hanzi flashcards app for Android

I ported my Hanzi J2ME application which I developed last year to help me memorize Chinese characters using my mobile phone. The original app was written for my Nokia phone which I lost last July, and now I ported it to Android to be able to use it on my current phone. It's been a while already since I did this, but I added some minor improvements today to speed-up loading data from the SD card, so I thought the time was right to write a little blog post about it. The porting process was pretty much straight-forward, but I had to learn a lot about the Android application model, since I never did anything on Android before. Using Eclipse and the Android SDK and emulator, it was not too hard to get it working. The data files are the same as for my original app, so there was no time wasted in re-entering text.
In the mean time I also got the official HSK level 3 word list (600 words), which I also included in the data set. Word lists (or card decks, to use the flashcards terminology) can be selected in any combination through a tree-list interface with check boxes. The only difference in operation is that I included touch gestures as an alternative to the 5-way navigation button in the J2ME app. The translation to touch is straightforward: the 4 directions are translated to swipes, while the center key is implemented as a tap action.
Source code is available on github.