For use on the desktop you can add the following two lines to the <buildthumbs> action (insert them just above the "inc(i);" line):
copy(plugin[get(thumbname)].scenetitle, scene[get(i)].title);
set(plugin[get(thumbname)].onhover, showtext(get(scenetitle)) );
Which will use the title="xyz" from your <scene>.
This works great, on a desktop, but onhover obviously doesn't exist on the iPad...
I would love to know how, on an ipad, you can open the thumbnails and have the "title" appear next to, on, or below the thumbnail... specifying the text style would be that much better... any ideas?