From the Publisher:
iGridd puzzles, also known as Griddlers or Nonograms, are picture logic puzzles in which cells in a grid have to be colored or left blank according to numbers given at the side of the grid to reveal a hidden picture. Some people compare iGridd to Sudoku. However, the iGridd puzzles always reveal a nice image as a result.This book consist of 137 iGridd puzzles, from small and easy up to big and complicated ones that may take several hours to solve. The solutions of the puzzles appear at the end of the book.This book also has a special type of iGridd puzzles called Triddlers with three directional grid.