I STRONGLY agree with the +/- correction, as any hi-fi amp does. Sometimes with high quality music and good headphones (I use often my HD600) it's just necessary to tilt a bit the reproduction curve, and doing it with the equalizer is a pain in the ass, and prone to "digital blurring" errors moreover. PLEASE, PLEASE provide this last perk to this fantastic app! Its quality with my Galaxy S3 is really hi-fi. A last humble suggestion: instead of a mono switch, creating a knob to blend progresively the two channels would be a nice luxury. With some not very well mastered materials the instruments