The Unofficial SmugMug Extension for Chrome is a free add-on that offers extra features for SmugMug site owners. Developed by Sherlock Software, this extension is specifically designed to help users administrate their SmugMug sites.

With the extension installed, users will find an "SM" button added to their toolbar. When viewing their SmugMug page, they can click on this button to access a menu of special features. These features include the ability to add a PayPal shopping cart to galleries, create a backup copy of customizations, and generate lists of folders and galleries in CSV and HTML format.

The extension also allows users to create permalinks to their galleries and show badges on image thumbnails to indicate that they have been collected from other galleries. Additionally, there is an advanced bulk editing tool for image titles, captions, and keywords.

For more information and assistance, users can visit the developer's website, which is linked from the "details" tab of the extension.