Thinkrolls is a well established series of logic apps -- all based on the idea that you move through a maze full of challenges. Success requires planning, as you use fans, elevators, trap doors and so on. So far, all the Thinkroll apps have been paid. This is a subscription version (you can download the first level for free), with more content, some stand-alone games and a new level editor that lets you make your own challenges. The word "code" in the title should not be taken literally. Games include Spot the Difference, Find the Odd One Out and concentration. There's a lot of content once you subscribe -- 14 basic levels, 18 easy levels and 18 hard levels. You must master the easier levels before you can advance. The level editor lets you drag and drop elements onto a grid. The entire experience is well designed and very easy to use. Progress is saved automatically for up to six players.