This tool allow you to package an extension which is already installed on your Joomla website.
It is useful for developers, as you can develop directly on a Joomla website and then build your zip file automatically (for the first release or even a new version of your extension).
It can also be used by any Joomla webmaster for transfer an existing extension (only files - no data) if you cannot find the zip file anymore.
Please report any bug, or extension which does not compile properly.
You must use this component in administration part.