My name is Raul Fernandez. Although I am a newbie in the freelancer world, I have worked with UML since UML 1.1 until version 2.5. This is an interesting project related to modeling and human computer interaction (HCI). I am an experienced information system developer and architect and I have worked with several case tools like Rational Rose, Visio, ArgoUML, Visual Paradigm and Enterprise Architects. Nevertheless, I could manage another tool of your preference. I suppose, but it is important to clarify that you need to document an application human-computer interaction. I also don't know if you have disponibility of the source in order to get the real name of the documented classes. But HCI has its own rich theories and practices.
As a plus: I could model it before starting with a chunk or module of the application in order to demonstrate you the feasibility of my proposal.
Please let me know if this project is available because it's a good fit for my career.
If you wish, I could send my resume.