In WP tabs pro, we are provide you placeholder, which is in Widget section. By using placeholder you can add any widget in placeholder except WP post tab pro widget and make them as a tab.
You can add Calendar, Archive, Text widgets etc. and other plugin widgets also you can add.
You have to just drag and drop widget into WP tabs Pro Placeholder and then add Tabs pro PH widget into theme sidebar or widget area, in which you want.
You can customize your tab, by Tabs pro PH widget. All necessary setting fields are available in widget.