Bind ships some example html attached to the themes.
It goes in those T/Q Files you see in the Views folder and they can be customized.
It is NOT a widget, since widget contents are saved in Orchard itself. They are "ad hoc shapes" that look just the same as widgets do. So its example code you can use in your site, or remove if you find no use for it.
To customize these shipped "widgets" you simply need to open each one (Dark has T1-T3, Q1-Q4 and Top) and edit either the title, the body of the shape or both.
You will have to attach any custom actions to the buttons in order to make them do stuff like sending emails.