Does anyone out there know how the hand gesture control works?

 

I have it switched on but when I move my hand across the screen nothing happens what am I doing wrong or not doing, any suggestions?

I find too fingers moving left to right/right to left works, you can see the bar that picks up your movement running along bottom off screen you just need to move it parallel to this I find 

sometimes it works then it doesn't. I just use the arrow

Thanks both,

 

I find it very hit, but more often miss