LiveFader

@IBDesignable Horizontal or vertical UIControl subclass that can start from bottom or middle of the control.

Demo

pod 'LiveFader'

Create a UIView instance in your storyboard and make it's class to LiveFaderView.
Or create a LiveFaderView programmatically.
Set the bottom or middle control style with the style property.
Set the horizontal or vertical control type with the controlType property.
You can bind a @IBAction to the LiveFader's valueChanged event from the storyboard or programmatically.
You can change the enabled/disabled/highlighted color styles from the @IBInspectable in storyboard or programmatically.
LiveFaderView is an open class, so you can subclass it to make it look anything you want, by playing with it's layers or adding new ones.

Custom scroll view subclass lets you edit all faders with a single pan gesture recognizer.
Set its isFaderPanningEnabled property to true.
It won't let you scroll in this mode because you will use the current pan gesture for editing faders instead of scrolling.
Finds all LiveFaderViews in itself and it's subviews recursively, feel free to add your faders in a stack view or a custom container inside your LiveFaderScrollView.

This library used in my apps in App Store, check them up!