turning a knob on the screen of an app

Hi al I'm trying to use an app called hamsphere which seems to be reasonably accessible unlike their desktop application. This app has a tuning knob which you are supposed to turn clockwise and anti clockwise to tune different frequencies. How would you go about turning such a knob? Could you use the rotor for this and is there any way to activate and interact with the rotor using a braille display on ios 7? Thanx for any help Andre

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#1 Hi, I have a hard time

Hi, I have a hard time with knobs on iOS devices. In Garage band on my iPhone there are knobs for the amp controls. Vocie-over tells me to double-tp and hold then drag to adjust them. I'm not sure which way to drag after i double tap and hold though! Sorry I couldn't be much help but try double-tapping and holding, then drag your finger left, right up or down and see what happens.

#2 amp in garage band

I have nothing to amplify but am guessing that since it makes the sound that it is supposed to make when you double tap and hold, sliding up and down will do the trick. Remember you are in landscape mode so up and down will be perpendicular to what it is in portrait mode.