If you enjoy logic puzzles, you might enjoy today's Amazon's Free App of the Day, CrossMe Color: http://www.amazon.com/gp/product/B00...m_1_tw_app_fad

These are puzzles, called nonograms (not to be confused with nomograms, which aren't puzzles), and are described in great detail in Wikipedia: http://en.wikipedia.org/wiki/Nonogram

I've probably spent far too much time playing the monochrome game, CrossMe, which was Amazon's Free App of the Day a few months ago.