If you, like I did, want to use a graphical tool to enter state machines and, like I did, get convinced to use proper event driven software development when programming your Arduino to get the best battery life possible and are, like I am, way to lazy to program all that event queues and dispatching yourself you may, like I did, stumble upon the Quantum Leap Framework. It sounds good on paper, being open source but still rather professional and mature.
The framework is portable to Arduino devices and there even is a special release for Arduino and da rather good application note serving as a tutorial.
If it would just work.