All users will have the Kitchen Sink -- the second row of icons displayed in Visual mode -- for both the Page and Post Editors.
When this plugin is activated, all users will see the second row of icons ("The Kitchen Sink") displayed in the Admin panel's Page Edit and Post Edit Visual tab. Clicking the first row's Kitchen Sink icon will only momentarily hide the second row of icons.
The Other Notes (Troubleshooting section), Installation and FAQ tabs provide helpful information, both to get started, and to address concerns you might have about the plugin not working as you were expecting it would.
Introduced in Version 2.0, a Settings page provides a large amount of Troubleshooting information, most notably a Users section that indicates if any Users on the current Site have the "Disable the visual editor when writing" checkbox set in their User Profile, as this prevents them from seeing the Visual Editor and the Kitchen Sink that is part of it.