This is not an iPhone app yet, but a downloadable (for Mac/windows ) gizmo for your desktop that you can play with whenever the mood takes you. you just throw a photo on it and wait a few secs, (dont wear headphones :) for the transformation to happen. It will turn your jaded/dull or alright photo into a retro polaroid with finger prints, vignettes, scratches dust
I dont suppose they had Polaroids in the Wild West but if they did, they would probably look like these.
I found these digital Vintage polaroids whereby you can incorporate your own images. You can do this in Photoshop or an image software program that has layers.. This is a page of polaroid bases that have been grunged and stained so they look really old. You can download them

I used some of the new Cowgirl Collection (over 80 images) which for a donation to art-e-zine you can get
These photos used for Poladroidation were taken in at Las Dalias, the Saturday Hippy Market in Ibiza a few years back. Lots of colourful indian fabrics, chilled vibes and laidback music. Nice to relive a few memories
Free Counters
The original Polaroid Land Camera instant prints with self-developing film more info .Hard to find film and expensive at that, makes this out of reach for all but the real purists. So this easy software can ease the pain
and colour variations. Not bad for free. As it makes the photo a square, you may want to crop your photo first.You can stop the developement at any point to get a more faded reto look. It really is easy. Useful to stick in Journals, make a note on the area below or crop it off.
Find it
here Poladroid.