Nonograms Pro is a lovely version of Nonogram puzzles (aka Griddlers, Hanjie or Picross) for your iPhone.
Nonograms are logic puzzles that use number clues around a grid to create an image. Each clue indicates a group of contiguous squares of like color. Between each group there is at least one empty square. The clues are already in the correct sequence. Groups of different colors may or may not have empty squares between them.