Back when Instamatic got popular, I was using an N900 and of course didn't have access to the app. So I made my own, by piping images over SSH to a server running a couple of Imagemagick scripts that applied one of a few LUTs I cooked up, and optionally some vignetting maybe.

Worked OK, was completely pointless of course.

Edit: I meant Hipstamatic. It's been a while.