Thanx for sharing this app, but I can get it to work on my Air. Is there some trick to it?
You should be able to just turn it on and have it work - I know that often Apple changes a few little things in newer revisions of their trackpads, and the developer winds up needing to update Jitouch for them, so you might want to try e-mailing them and asking them if it has been confirmed to work on your Air. Here's how I have mine set up working right now if it helps: