使用加速度计(和陀螺仪)进行iOS手势识别

I would like to detect gestures on an iOS device using the accelerometer and perhaps the gyroscope. The Application should detect movements like drawing a circle or a rectangle in the air. I've found several papers on gesture recognition on iPhones but there is no actual code which I could use. I wonder if there is a library which could assist me in approaching this goal in any way? If not, I have to start building one on my own! :) Thanks in advance! MarkusI would like to detect gestures on an iOS devic