But damn, I hate to see anything popularize AIR apps. Also consider OmniGraffle if you are looking for prototyping :)
Really don’t want to rain on parades. Just want to make sure people know there are (IMO better) alternatives.
What am I missing?
I have used both. Though I only used the Flash version of Balsamiq, since my AIR installation refused to work.
Perhaps you downloaded it, dragged some things onto a canvas, and then never picked it up again. You missed a lot of great stuff. It's a thoughtfully designed (and very nerdy) app.
The page is not forthcoming in terms of tech. It's "hosted." What do I interact with? Flash? Native?