In the backend there are some options for styling of the tooltips that don't seem to have an effect. Many options are marked "beta". But as far as I tested the extension, it works well and I found it easy to use.
I'm really grateful the author wrote this. Excellent.
I had one issue: a component appeared twice on a page.
Here comes the author's support: Problem reported Friday night, fixed update delivered Saturday early morning ...
Only issue I had was that the thumbnail spans had a greater size than the thumbnails. There are constant numbers of pixels added in ppgallery.php, near line 363. Why these are added is beyond me ... I simply deleted those constants, now everything's fine. Thank you!