ViragDevTool is Lua World of Warcraft addon for addon-developers.
Functionality is similar to a debugger.
This addon can help new developers to understand WoW API.
Main idea is to examine WoW API or your addon's variables in table-like UI.
Much easier to use then default print or chat debug
The latest version can be found here :
Full README on Github Page
Demo video: (UI changed, but functionality is still the same)