To change extension's options, right-click on the toolbar icon and select "Options":.
Then just check/uncheck the respective checkboxes:
If you check the "Open in current tab" checkbox, the pages will be opened in the current tab (replacing the current page). By default it is unchecked (pages will open in new tab).
The "Show URLs" option will just add the url to each menu item. When selected, the drop-down menu will look like this:
Keep in mind that this option will make the menu "longer" (it uses 2 lines per item). If you want to keep thins compact (and without scrollbars) -- just uncheck this option...
Remember that if you don't need this extension anymore, you can remove it at any time (just right-click on the extension's icon and select "Remove from Chrome")