It's really annoying that only the image fades when you tap on a button. By subclassing this, the entire button will fade.

FadeWhenHighlightedButton.swift

import UIKit

class FadeWhenHiglightedButton: UIButton {
    private var initialAlpha: CGFloat!
    
    override var highlighted: Bool {
        didSet {
            alpha = highlighted ? initialAlpha - 0.4 : initialAlpha
        }
    }
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        commonInit()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }
    
    private func commonInit() {
        initialAlpha = alpha
        showsTouchWhenHighlighted = false
        adjustsImageWhenHighlighted = false
        reversesTitleShadowWhenHighlighted = false
    }
}