How to add Modules to different Tabs?

Is there an easy way to add modules to tabs other than the Modules tab? E.g. reports to the Reports tab? Or even to a new tab?

I see some stuff in the repository that looks promising... specifically the Manager Manager http://modxcms.com/ManagerManager-1565.html

However, I’m still unclear how MODx associates certain functions with certain tabs. I’ve looked through the database and I can’t seem to find where the built-in "modules" live. I can see the URLs in the manager passing around stuff like "?a=53" for the different manager actions, but I can’t see what unique id that’s referring to... I assumed it was a database index. Am I wrong?

Thanks!