iPhone version of Abaia, one of the strongest Mac OS X chess programs, and one of the best and most popular open source chess programs ever.

Features:
• Clearly stronger than Chess Genius 2.0 and t Chess Pro 1.2.0, but free!
• Plays aggressive and dynamic chess, and is not afraid of sacrificing material for initiative or attacking chances.
• Adjustable playing strength: Choose between 100 strength levels.
• Choose between several styles of play: "Passive", "Solid", "Active", "Aggressive" or "Suicidal".
• Big, deep and varied opening book. Choose between three levels of book variety.
• Displays book moves and engine analysis, including search depth, evaluations and main lines.
• Allows you to easily set up board positions.
• Able to think during the opponent's time, for maximum playing strength (disabled by default, in order to save battery life).
• Supports saving and loading games to PGN files, and to send games by e-mail.
• Play against the machine, or play both sides, with or without book moves and engine analysis displayed on the screen.
• Uses convenient finger gestures for taking back and replaying moves.
• Choose from two piece sets and five color schemes.
• Complete source code available under the GNU General Public License.