The pilot reported that during the landing flare the airplane pulled to the left. He added power and moved the control stick to the right, but without success, and inadvertently stalled the airplane. The airplane landed left wing low and on its nose after falling about three feet. The light sport airplane was not equipped with a stall warning horn. The airplane’s flight training supplement states the following about stalls: “The stall is noted through light buffeting. At 2 kts. (3 mph) above the stall speed, the rudder becomes “soft”. When flying close to stall speed, only the rudder and elevator are fully controllable. The ailerons have less effectiveness in very slow flight.”