Mortis:
Me interessou essa parte: "Apply to be a beta tester when you register for the forum. Contributors get a free forever license for the debugger upgrade when it is released"É interessante vermos as regras, "free forever" é muito melhor!
Yes, it is "free forever" for all beta contributors (the more the better, hint hint) but it won't cost very much anyway 
http://www.visualmicro.com
You can see a slow but detailed overview of the Arduino debugger on youtube
Arduino debugger.
The first couple of minutes is for new Arduino users, the remainder shows basic debugging.
Sorry for using English