How everyone's missed this is beyond me. Tested with WordPress 3.5 and FireFox 17.01, Chrome Version 23.0.1271.97 m, Internet Explorer 6, Opera 11.64 and Safar 5.1.4 on Dec 15th 2012 - and it worked on ALL of them!
For the record, documentation and contextual help isn't too good, and support forum appears to have been abandoned.
How to make it work?
In theory there's a little downwards arrow to the right of the media uploader button which you're meant to press, and this triggers a popup, but content typed into this popup box (there are no formatting options displayed) comes out as a string, so forget that.
What you do instead - and it's no great hardship - is type
around the formatted text that you want to slide down.
If that doesn't come out right in this post, let me reiterate: you put standard shortcode containing the word EXPAND around the desired formatted text. The opening EXPAND is followed by any characters at all, which will act as an identifier for that block of formatted text. This way you can have multiple sliders on one page.
My list will be revealed
My pictures will be revealed
where I've left out the opening and closing shortcode tags.
Lovely plugin! Hope someone takes it over if it's been abandoned!