BeSly wrote the second part of their yab beginners tutorial. In this part, after first covering the basics, they walk through the process of creation an application, in this example, an app to create a bfs image. They cover the planning stage, creation of the program window and interface, among others.

If you haven't read the first part, you should, it'll give you the basics of this programming language. You can download yab's source as well using CVS and BeSly also offers a Help page for coding using yab. BeSly also offers others tutorials on their page, both in German and English, so be sure to check them out.