Back in 2008 when I bought my first Android device, I also started to explore the possibilities in developing for mobile platforms. At that time Android was at version 1.5, so I used the Android SDK 1.5 to develop my first application.
Since I wanted to make something fun (well more fun than just another notepad) I decided to port my Chip8 emulator MyCHIP8. The original implementation was done in C++/Directdraw.
It took me about half an hour to port most of the code to Java/Android. Below are some photos of MyCHIP8 running on my T-Mobile G1.
Photos
(Running Pong)
(Running Space invaders)
(Running Space invaders 2)