Microinteractions: The Secret of Great App Design https://uxplanet.org/microinteractions-the-secret-to-great-app-design-4cfe70fbaccf#.krul9e6lo
Button UX Design: Best Practices, Types and States https://uxplanet.org/button-ux-design-best-practices-types-and-states-647cf4ae0fc6#.dhpyrnr10