The classic Duke Nukem 3D iPhone/iPad game is now available for free for today only, this is considered as Best First Person Shooter game. Generally Duke Nukem 3D costs $2.99.
According to Developer:
With dozens of Game of the Year awards under his belt, Duke remains the King of Action. Larger than life action is what Duke is all about, mixed with humor and innovative explosive action in this 20+ hour game.