About State Diagram Editor
A compact, flexible tool for the design of Finite State Machines.

- Intuitive User Interface using Drag&Drop
- Simple Testing supported by visualized Execution
- Support for the Design of complex Models using FSMs in a Responder Chain
- Template-based Code Generation
- Easy Merge of Changes in Model and direct Code Changes
- Remote Execution of Diagrams from the Target Application

Read more: http://www.apple.com/downloads/macosx/development_tools/statediagrameditor.html