Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
UnfoldPrints - UnfoldPrints is an app that allows you to make photo collages and order them to print.
Pixel Art Studio - A purpose-built drawing tool for pixel artists
Lalalab - Print photos from your iPhone
Pixilart - A drawing app for delightfully retro pixel art
Picta Photo Print - Picta Photo Print is an app that allows you to place an order for online photo prints.