Instagram - Instagram is a mobile, desktop, and Internet-based photo-sharing application and service that allows users to share pictures and videos either publicly, or privately to pre-approved followers.
FotoFlexer - FotoFlexer is the most powerful online photo editor in existence.
Manual Camera for iPhone - Custom exposure for your iPhone camera
Photoshop.com - Photoshop.
Pixlr - Pixlr® makes it easy to transform everyday images into stunning works of art.
Fun Photo Box - FunPhotoBox is a free photo editing device where you can make clever pictures from your photographs.