I think there's very little to showcase such apps @timbirks but i've seen a nice kids book app developed by tinytouchtales dot com - just google them.
Apart from that, seems to be dominated by 2D games - hence Stencyl's homepage moniker 'Create Amazing Games Without Code.'
I too am using it to build interactive kids apps - books and learning experiences. I am also learning Corona SDK just to keep my options open if one or the other fails to deliver :-)