De MonsterDebugger is an Air application from De Monsters that comes with a handy set of features. One of its better known features includes editing properties and calling methods at runtime. This alone definitely makes it a nifty little debugger. It also displays xml as a tree that is collapsable and expandable. At times the overall tree structure can be somewhat clunky but it's enough to get me using it. The only catch with these perks is that all your properties and methods need to be public so that they are accessible.

To enable MonsterDebugger in your application instantiate it first like this:
this.monsterDebugger = new MonsterDebugger(this);
this is the reference to the root of the application. This line alone allows to modify methods and properties throughout your application.

To make a trace you would write this:
MonsterDebugger.trace(this, xml);
this is the reference targeted object.

One last thing to consider is that you export the classes needed for MonsterDebugger from the Air application to the client side folder. To do this navigate to the following in the Air app:
File > Export Client Class
Point to the folder that contains all your application's classes

Download the Air application Version 2.51