Blockis
Blockis is a standard tetris-type game. Only one level and no sound.
Download: GetJar.
Source code

Aritm
Aritm trains you in simple mental calculation. This program teaches its users the addition, subtraction, multiplication, and division tables. It employs a very effective method, which makes the process short with these useful tables.
Download: GetJar, Phoload, Android (check Menu/Settings/Applications/Unknown Sources & select J2ME Runner from Netmite at first run of Aritm on Android).
Source code Video

Week # ISO
Week # ISO converts between dates and week numbers (ISO). More functions: adding days, adding business days, timer, moving holidays.
Download: GetJar.
Source code
DriveReporter
DriveReporter keeps track of vehicles.
MIDlet source code
Servlet source code (Java)
Server source code (PHP)