A brand new app, Peg + Cat: The Tree Problem, is not only cute and fun to play, but it gives preschoolers a way to explore the notions of spatial reasoning, sequential thinking, and logic. The set up is simple: Peg needs to help Cat down from a tree — and not just a single tree but a series of them in six different settings. The challenge for kids is to manipulate different items to help Cat get down from the tree and unite with Peg. On the farm, they can pour water on flowers to help them grow just tall enough to provide a step ladder down to the ground. In the more urban “Mathtropolis,” Cat is stuck in a tree and the only by placing beams on a series of girders can he reach park level to join Peg. Familiarity with the PBS TV show Peg + Cat not required!