Euchre is self-explanatory. It's an extremely strong program and will challenge even the best players. There aren't any difficulty levels, just one. Hard.
Euchre is also cross-platform because it was written in Java.
Proof is designed to quickly preview sets of exported documents and send them to a final destination when finished.
You may want to watch this video for an explanation of how it works.
EasyGPA is a simple GPA calculator for the iPhone. It works on iOS version 3.1.3, but is known not to work on iOS 4.
As a bit of history, EasyGPA was NovaStorm Software's first ever application.