Great article!
Just a detail of code styling, if you are using SwiftLint use this code to prevent warnings.

UIView.animate(withDuration: 1, animations: {
    self.bonacinno.backgroundColor = .brown
    self.bonacinno.frame.size.width += 10
    self.bonacinno.frame.size.height += 10
}, completion: { _ in
    UIView.animate(withDuration: 1, delay: 0.25, options: [.autoreverse, .repeat], animations: {
        self.bonacinno.frame.origin.y -= 20
    })
})