It's all yours.

You will find a lot of code in C, C++ and C#, mostly for basic concepts training purposes.

There is a snake game and a words mixer code in C, mostly to train string/char manipulation, 
there is also a Plugins installer for some Linux distros. That Plugins install app also
received an interface, which was firstly writed using raw GTK but later 'constructed' using 
Glade.

In C# there is TrackingTool, a huge application for finantial control on Pharmacy chain networks 
used as final project for my degree.

As I said, it's all yours if you find some utility for ir :)