I think it needs to be visually simple and act like a fader IMHO. Take up the minimum amount of space, and work intuitively like a fader in that you dab your finger and drag and let go when you see the setting (named tick) that you are seeking.
If you could hide the numeric value and ticks on a fader, you'd have the result I reckon, keeping it as simple as possible. Maybe an option on a fader / xfader...PickList...which when ticked just displays the currently selected value in the border of the control, with no numeric value or tick marks.