The Story of Christoph Niemann's Petting Zoo App, an illustrated article from The New Yorker. "I had this idea of making a simple line drawing that one could naturally manipulate by touching and swiping. How hard could that be?"
Sweet and simple - be merry and Let It Dough! (goofy SLNYT filter)
Christoph Niemann illustrates: his sons' obsession with the NYC subway (previously), bathroom tile art, New York cheat sheets, and his experiences with coffee (illustrated with coffee on napkins). Check out his excellent portfolio of illustrations and don't miss the ones on illustrating. You can see Niemann talk a bit about his work here.