One of the things that irritates me the most about iOS is the notification system. Incoming notifications often interrupt whatever my iPhone is doing and forces me to take some action to clear the notification and get back to what I was doing. Android handles notifications far better. they are generally unobtrusive and don’t get in the way.
I came across this post on TechnoBuffalo with a video of a concept notifications app for iOS. It looks like an improvement, for sure, although having this run through a separate app seems like a waste of space. It should be part of the core OS.