I want to explain some key points of the App here, in all the gory details. So if you only want to use it, you don't need to know all this stuff. But it won't hurt.
Clockring is really an exercise on LocalNotifications. It started after looking up the LocalNotifications API. A Notification it's an alarm that you can set at a predefined day & hour and shows you an alert, playing an optional sound. But the alert its not mandatory too. So I thought "why not just play a sound as an alert". From here I noticed that the iPhone clock doesn't play any sound every hour, and the rest is history
I use this project as a Lab App, to test ideas and code. For example, I included iAd to test how that worked (both in code and in money). In v1.1 I'm experimenting with user interface, animations and so on. Probably AdMobs, too.