Let me first say that this is an fantastic plugin. I love the way it works. I just started using it and am having just one issue. I'm hoping to use this with the Featured Image, but I'm not getting the Featured Image Gallery Meta Widget (shown here)
I do have the Featured Image box in my theme(s) though.
I made sure everything was enabled in the Screen Options, but no luck. I've tried it on two different sites & servers, one of which, I enabled both the Twenty Eleven & Twenty Twelve Themes and disabled all other Plugins. I can get it to work using the shortcode image path like so...
[gallery modal="true" thumbnail="/path/to/image.jpg"]
And while this works fine, the site that I'm hoping to use it on, there will be non technical users and hoping to tie it into the "Featured Image" so that they don't have to deal with the shortcode like that.
Have you seen this happen previously?
Thanks again for this plugin. It's perfect for a project I'm working on.