User Interface - tommy9/Rubberduck GitHub Wiki
Menus
Rubberduck integrates (seamlessly?) with the VBE and exposes its functionality mainly through menus.
In the main commandbar:

In the code pane context menu:

In the VBE's own Project Explorer context menu:

In the UserForm designer's context menu:

Which commands are available when, depends on the current state of the parser, and sometimes the current selection.
Rubberduck command bar
The Rubberduck command bar displays the current parser state and various information about the current selection:



The Rubberduck command bar can be docked at the top or bottom of the IDE, and serve as some kind of status bar.

If Rubberduck can't parse the code, parser state will be "Parse Error". When this happens, clicking the status label (which is actually a button) will bring up a Search Results toolwindow and add a Parser Errors tab.
Toolbars
Most toolwindows have a toolbar.

The Source Control refresh works differently, but otherwise the refresh button in all toolbars synchronizes Rubberduck with the actual code in the IDE.
When present, the copy button copies the data in the grid in various formats that can be pasted in Notepad just as well as in Excel.
When present, the settings button brings up the corresponding tab in the settings dialog.
A grouping menu allows choosing how items are grouped together; by category, or by location/module:
