Flex - Debug Application - Flex provides excellent capability of debugging flex code and Flash Builder 4 has an excellent built-in debugger and debugging perspective support.
Working with the Debugger in Adobe Flex Builder
Preparing Flash and Flex Applications for Testing Under the Debug Version of Flash Player
Flex - Deploy Application
Flex - Useful Resources
ios - I am unable to get FLEX Debugger to work after installation - Stack Overflow
Flex Tutorial, PDF, Apache Flex
Flex - Life Cycle Phases
Debugging superpowers with FLEX
Flex Tutorial, PDF, Apache Flex
Packt+ Advance your knowledge in tech
Flex - Move3D Effect