Stockfish Chess

Strong free chess program.

Features:

* Free, but much stronger than most commercial iPhone chess apps!

* Plays aggressive and dynamic chess, and is not afraid of sacrificing material for initiative or attacking chances.

* Adjustable playing strength.

* 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, sending games by e-mail, and transferring PGN files between your device and your computer.

* Play against the machine, or play both sides, with or without book moves and engine analysis displayed on the screen.

* Choose from nine piece sets and eight color schemes.

* Complete source code available under the GNU General Public License.