Flippy the Train vs Rule It

Build a train track to solve digital circuitry puzzles! Flippy the Train rides the rails, flipping switches to model basic digital circuitry: NOT, AND, and OR logic gates. After building these basics, reuse them in larger tracks to create the more-complex XOR gate and half-adder. What is the fewest number of track segments required to build a half-adder? Includes a sandbox mode for creating arbitrary track for Flippy to ride.

Find the rule behind a sequence of cards.  The rule can be very easy like: "Color of new card must be different from color of previous card."  or hard like:  "If number of previous card is bigger than 7 then shape of new card must be different from shape of previous card, if not then shape must be the same." At the start of the game 4 cards are placed for you. If you want more cards just keep pressing the "I don't know yet" button. Once you discover the rule, you can use the "Yes" and "No" buttons to correctly place new cards. You can always go back and press the "I don't know yet" button again. The more cards you need before you can correctly place 6 cards in a row, the fewer the points you will win. A New game will be available every Friday for you to play. Friday games are the same for everyone playing the app. You can also buy new games and choose if you want to play an easy, medium or hard game. The new game will use one of the possible rules for the difficulty level you choose.