AnimatedButton.swift

import UIKit
import PlaygroundSupport

class AnimatedButton: UIButton {

    var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }

    var highlightAnimation = false

    override var isHighlighted: Bool {
        didSet {
            guard highlightAnimation else { return }
            let transform: CGAffineTransform = isHighlighted ? .init(scaleX: 0.95, y: 0.95) : .identity
            UIView.animate(
                withDuration: 0.4,
                delay: 0,
                usingSpringWithDamping: 0.5,
                initialSpringVelocity: 3,
                options: [.curveEaseInOut],
                animations: { self.transform = transform }
            )
        }
    }
}

class MyViewController : UIViewController {

    lazy var button: UIButton = {
        let button = AnimatedButton()
        button.setTitle("Subscribe", for: .normal)
        button.backgroundColor = .red
        button.contentEdgeInsets = UIEdgeInsets(top: 10, left: 40, bottom: 10, right: 40)
        button.cornerRadius = 10
        button.highlightAnimation = true
        return button
    }()

    override func loadView() {
        view = UIView()
        view.backgroundColor = .white
        view.addSubview(button)
        button.translatesAutoresizingMaskIntoConstraints = false
        button.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        button.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
    }
}

PlaygroundPage.current.liveView = MyViewController()

https://infinum.co/the-capsized-eight/10-minute-tips-to-make-your-iOS-app-more-interactive