From something ago i use CameBag (a popular app for iPhoneographer’s) on my iPhone. This week i buy the desktop version for mac, its a very simple program so you can have quick and funny results.
Please watch Getting Started With CameraBag for Mac from nevercenter channel on Youtube
Here the result using CameraBag
Using Helga Filter
Using Instant Filter
Using Multi-filter option (Helga and Instant)
LINKS:
CameraBag Website: http://www.nevercenter.com/camerabag/
CameraBag on iTunes: http://www.itunes.com/apps/camerabag