Basics

The game of Quarto can be compared to tic-tac-toe taken to the next level.
 
Instead of 2 types of pieces (x's and o's) there are 16 unique pieces. Each piece is defined by 4 qualities. The 4 qualities of the original game are:
color: black or white
height: tall or short
shape: square or round
density: hollow or solid
The present incarnation of the game has several sets of pieces to choose from, each with their own four unique binary qualities.
 
To win the game, you must get a Quarto (4 pieces of the same quality in a grouping). A grouping is dependent on whether you are playing normal or advanced rules:
Normal: lines (row/column/diagonal)
Squares: the nine 2x2 squares
Advanced: lines or 2x2 squares
This may sound simple, but the trick is that you don't choose your piece, your opponent does.
 

Game Mechanics

New Interface

In the intro screen: set your preferences by tapping the "prefs" button to bring up the preferences screen. Start a game by tapping on either the 1P or 2P buttons.
 
To choose a piece for your opponent, tap that piece with the stylus. It will move up to the box at the top of the screen.
 
To Place a piece on the board, tap the square on the board where you want the piece to go, it will go there.
 
When someone gets a Quarto, the corresponding squares on the board are highlighted to show you. Hit the Return button to return to the intro screen.
 

Old Interface (prior to V 1.0.7)

In the intro screen: you need to enter information by keying in letters (0-9 for difficulty level, c=computer starts, p=person starts, a=2 person game, b=1 person game). Once you start a game, the action is pretty simple.
 
To choose a piece for your opponent, drag it from the piece pile to the box at the top of the screen, then hit the Go button.
 
To Place a piece on the board, drag the piece from the box to the location on the board, then hit the Go button.
 
When someone gets a Quarto, the corresponding squares on the board are highlighted to show you. Hit the Go button to return to the intro screen.
 

Misc

The normal hard buttons are captured by Razor! To get back to the launcher, tap the application silk-screen button (can be done at any point in the game).
 
There may still be some bugs in it. I have error checking and alert dialogues all through the code, so if it brings up an alert on you, that just means there are a few things in there I still need to resolve. Hopefully, if I've programmed it correctly, you shouldn't see any even in the 1 person game.