Puzzle Set Game app for iPhone and iPad

Set Game is a real-time card game. The deck consists of 81 unique cards that vary in four features across three possibilities for each kind of feature: number of shapes (one, two, or three), shape (diamond, squiggle, oval), shading (solid, striped, or open), and color (red, green, or purple). Each possible combination of features (e.g. a card with three striped green diamonds) appears as a card precisely once in the deck.

To increase your score you have to make a set. A set consists of three cards satisfying all of these conditions:

They all have the same number or have three different numbers.
They all have the same shape or have three different shapes.
They all have the same shading or have three different shadings.
They all have the same color or have three different colors.

You can ask for a hint but your score will be decreased.

The game will finish when there are none sets left to be made from the remaining cards.