Hi! I've just passed a university subject which made me do a medium console-based game in Java. I had to do the design first with UML and then code the game.
I just found useful the Domain model (the first aproach of what's the point of the program) and the Class Diagram (what you really look when you are about to code), there was a lot of very heavy diagrams (Sistem sequence diagram) that I found that was larger and harder to draw a diagram than coding directly and well-commented because there were simple loops over a collection searching for a match.
What do you think about UML? do you think it's necessary to do all the diagrams (including all classes, attributes,methods...)of an application and then code?, or do you think the design model is just to not to code directly but have an idea about the classes that would have your application and the main methods?