iOS Pick: Circuitry
Leo Laporte's app cap from iOS Today 352 is Circuitry. This is a game that was recommended by Steve Gibson. This is a logic game that will help you understand Boolean algebra, logic gates, and digital circuits.
Circuitry has 21 problems that give you direct interaction with logic circuit diagrams. You'll construct solutions to logic gate problems by linking AND gates, OR gates, and XOR gates. As you progress through the levels, you'll unlock more logical elements. Then you can use all of these circuits in a Playground Mode to create interesting things.