Swift 4 Playground (building off of the CustomUIView.playground) that shows how to setup multiple animations as view extensions to keep the view controller simple to read - somewhat.

AnimationExtensions.Playground

//: Playground - noun: a place where people can play

import UIKit
import PlaygroundSupport

extension UIView {
    func asCircle(){
        self.layer.cornerRadius = self.frame.width / 2;
        self.layer.masksToBounds = true
    }

    func fadeIn(_ duration: TimeInterval = 1.0, delay: TimeInterval = 0.0, completion: @escaping ((Bool) -> Void) = {(finished: Bool) -> Void in}) {
        UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseIn, animations: {
            self.alpha = 1.0
        }, completion: completion)  }

    func fadeOut(_ duration: TimeInterval = 1.0, delay: TimeInterval = 0.0, completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in}) {
        UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseIn, animations: {
            self.alpha = 0.0
        }, completion: completion)
    }

    func shrinkView(_ duration: TimeInterval = 1.0, delay: TimeInterval = 0.0, x: Double = 0.5, y: Double = 0.5, completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in}) {
        UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseIn, animations: {
            self.transform = CGAffineTransform(scaleX: CGFloat(x), y: CGFloat(y))
        }, completion: completion)
    }
    func growView(_ duration: TimeInterval = 1.0, delay: TimeInterval = 0.0, x: Double = 1.2, y: Double = 1.2, completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in}) {
        UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseIn, animations: {
            self.transform = CGAffineTransform(scaleX: CGFloat(x), y: CGFloat(y))
        }, completion: completion)
    }

    func popView(){
        self.growView(0.2, completion: {
            (finished: Bool) -> Void in
            self.backgroundColor = .white
            self.fadeOut(0.2, completion: {
                (finished: Bool) -> Void in
                self.shrinkView(0.1)
                self.fadeIn(0.1, completion: {
                    (finished: Bool) -> Void in
                    self.transform = .identity
                    self.backgroundColor = .blue

                })

            })
        })
    }

    func colorFade(_ duration: TimeInterval = 1.0, delay: TimeInterval = 0.0, swatch: UIColor = .gray, completion: @escaping (Bool) -> Void = {(finished: Bool) -> Void in}) {
        UIView.animate(withDuration: duration, delay: delay, options: UIViewAnimationOptions.curveEaseIn, animations: {
            self.backgroundColor = swatch
        }, completion: completion)
    }
}

class MyView: UIView {

    let label = UILabel()

    func updateText(_ text:String?) {
        guard let text = text else { return }
        label.text = text
    }

    override init(frame: CGRect){
        super.init(frame: frame)
        label.translatesAutoresizingMaskIntoConstraints = false
        label.text = "MyView!"
        label.numberOfLines = 0
        label.textColor = .red
        label.textAlignment = .center
        self.addSubview(label)
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        label.frame = bounds
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
} // end MyView


class MyCollectionViewCell: UICollectionViewCell {

    override func awakeFromNib() {
        print("awakeFromNib")
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        self.asCircle()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

class MyViewController : UIViewController, UICollectionViewDelegateFlowLayout, UICollectionViewDelegate, UICollectionViewDataSource {

    // MARK: - Properties
    // views
    var headerView = MyView()
    var selView = MyView()
    var collectionView: UICollectionView?

    // attributes
    var numberSelected = 0 // track this

    override func loadView() {
        let view = UIView()
        view.backgroundColor = .black
        self.view = view
    }

    // MARK: - LifeCycle
    override func viewDidLoad() {
        super.viewDidLoad()
        setupHeader()
        setupCollection()
        setupSelection()
        setupStack()
    }


    // MARK: Methods
    func updateSelectedCount(_ upOrDown:String) {
        switch(upOrDown) {
        case "up":
            numberSelected += 1
            headerView.updateText("Another one bites the dust")
        case "down":
            headerView.updateText("Sorry")
            if numberSelected > 0 {
                numberSelected -= 1
            }
        default:
            print("not up or down")
        }
    }

    // MARK: CollectionView Methods

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 40
    }

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: 50.0, height: 50.0)
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "MyCell", for: indexPath) as! MyCollectionViewCell
        cell.backgroundColor = .gray
        return cell
    }

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        let selectedCell = collectionView.cellForItem(at: indexPath)
        // animate that Cell!
        selectedCell?.popView()
        updateSelectedCount("up")
        let selected = String(describing: indexPath.row + 1)
        let selString = "You selected cell #\(selected) for a total of \(numberSelected)"
        selView.updateText(selString)
    }

    func collectionView(_ collectionView: UICollectionView, didDeselectItemAt indexPath: IndexPath) {
        let deselectedCell = collectionView.cellForItem(at: indexPath)

        deselectedCell?.colorFade(0.2)

        updateSelectedCount("down")
        let deselected = String(describing: indexPath.row + 1)
        let selString = "You deselected cell #\(deselected) for a total of \(numberSelected)"
        selView.updateText(selString)
    }



    // MARK: SetUp Methods

    func setupHeader() {
        headerView.updateText("Update")
    }

    func setupCollection() {
        let frame = self.view.frame
        let layout = UICollectionViewFlowLayout()
        collectionView = UICollectionView(frame: frame, collectionViewLayout: layout)
        collectionView?.delegate = self
        collectionView?.dataSource = self
        self.collectionView?.backgroundColor = .black
        self.collectionView?.register(MyCollectionViewCell.self, forCellWithReuseIdentifier: "MyCell")
        collectionView?.allowsMultipleSelection = true
    }

    func setupSelection() {
        selView.updateText("None Selected Yet")
    }


    func setupStack() {
        let stackView = UIStackView(arrangedSubviews: [headerView, collectionView!, selView])
        stackView.axis = .vertical
        stackView.distribution = .fill
        stackView.alignment = .fill
        stackView.spacing = 10
        stackView.translatesAutoresizingMaskIntoConstraints = false

        // add some component constraints
        let headHeight = headerView.heightAnchor.constraint(equalToConstant: 50)
        let selHeight = selView.heightAnchor.constraint(equalToConstant: 50)
        stackView.addConstraints([headHeight, selHeight])

        view.addSubview(stackView)

        //autolayout the stack view
        let sH = NSLayoutConstraint.constraints(withVisualFormat: "H:|-20-[stackView]-20-|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["stackView":stackView])
        let sV = NSLayoutConstraint.constraints(withVisualFormat: "V:|-30-[stackView]-30-|", options: NSLayoutFormatOptions(rawValue:0), metrics: nil, views: ["stackView":stackView])
        view.addConstraints(sH)
        view.addConstraints(sV)
    }
}

PlaygroundPage.current.liveView = MyViewController()

The code above can be pasted into a playground to get a live view. The behavior on select and deselect is different because the animation is based on the view level. If an animation is in the cell, say for a condition like "isHighlighted" - the animation would be the same when selected and deselected.