title: Animation Corresponding to UITimer
body: <p>I am coding a game in Swift where the player has to make a move within a second, or else time runs out and he/she loses. How can I make an animation that runs every second, resembling the one in the top of Snapchat stories, where it is a filled in circle that slowly "wipes" away in a circular motion like a windshield wiper? Is it just a second-long GIF that I loop every second? Is there a way to do this with native UIKit graphics?</p>