Tab Merger от Simple Tasks

By pinning this extension to the toolbar, you can simply click the extension's icon to instantly merge browser tabs into a single window.

To merge the tabs of all non-private windows (including minimized ones), click the icon on the toolbar of a non-private window.

To merge the tabs of all private windows (including minimized ones), click the icon on the toolbar of a private window.

It is not possible to combine private and non-private tabs into a single window (browser limitation.)

Data Collection:
Absolutely nothing.