This extension is an application that lets you view the location in Google Maps/Earth and vice versa, depending on which tab is currently active.

If you want to see a specific location opened in Google Maps/Earth, you need to open the website from the browser. This is because the code of Google Maps/Earth must be included in the website of Google Maps/Earth in order to work.

On the other hand, if you want to see a specific location opened in Shadowmap, you only need to click the icon of the extension that allows you to open Shadowmap in the current tab of the browser.

If you have Chrome, you can view the source code of the extension on Github.