console - Mozilla | MDN
https://developer.mozilla.org/en-US/Add-ons/SDK/Tools/console#Logging_Levels
The logging level defaults to "error".
extensions.sdk.console.logLevel: if set, this determines the logging level for all installed SDK-based add-ons.
This includes add-ons being developed using the Extension Auto-installer.
traceGL
https://trace.gl/
With traceGL you can see all JavaScript codeflow, in a high performance webGL visualiser. Its like an oscilloscope, for code.
traceGL
https://trace.gl
With traceGL you can see all JavaScript codeflow, in a high performance webGL visualiser. Its like an oscilloscope, for code.
FirePHP - Firebug Extension for AJAX Development
http://www.firephp.org
"All data is sent via a set of X-FirePHP-Data response headers. This means that the debugging data will not interfere with the content on your page. Thus FirePHP is ideally suited for AJAX development where clean JSON or XML responses are required."