In this project throughout the whole semester, we are asked to target on an open-sourced project with 100,000+ lines of codes, understand its design patterns, and extend some functionalities of it. At the end, we pick up a open-sourced music player, figure out how Android works from scratch, add a shortcut for that app in home screen, and add a panel for users to determine the behavior of playlist randomness: “default”, “shuffle”, or “not shuffle”.