Get your boss a free copy of Visual Use Case. He can write requirements, user stories, list actors, etc and it will automagically spit out UML chart that you can use to visualize the flow when you code. You can get an upgrade to TopTeam Analyst and that will also give you swim lane diagrams plus manage end-to-end Requirements Traceability for Business Applications, Products and Medical systemsmore. Here is the free version:

http://www.visualusecase.com/download-visual-use-case-person...

Here is a video about the product you can share with him:

http://fast.wistia.net/embed/iframe/eamru13sx5?autoPlay=true...