JXN BLK pointed me towards this great repository of Mobile UI patterns compiled by Mari Sheibley. The screen grabs are broken down into a number of categories - Splash screens, Notifications, User profiles, etc - to show what works and what doesn't. It becomes abundantly clear, pretty fast, that alot of UI design is extremely cluttered. The best designs are those that keep it incredibly simple.. though I suppose that's a statement that applies to all design, not just mobile.