A feature added a little while ago that you may have missed is the ability to create a thumbnail list of galleries.
Use this shortcode in your post or page or custom code block:
[ showgalleryplus covers=2654,2627,2622,1594 thumbs=150]
the numbers are the gallery IDs. Thumbs is pixels width. (Don’t include the space after the [ as that is there so this doesn’t get shortcoded itself!)
The thumbnail used is the first image in the gallery.
Setting a URL and description for the gallery
In each gallery, enter a URL (usually the page that displays the gallery) for each gallery in the Excerpt field enclosed in url: and :url . e.g. url:http://mygallery.com:url
Any other text in the Excerpt field will display as the gallery description
The output will look something like the following and can be formatted with custom CSS:
CSS classes are: