Main interface as MainWindow.xib
Add AppDelegate object to MainWindow.xib
Create a window object in MainWindow.xib
Set window as a property
Set AppDelegate as MainWindow’s delegation
Change background color from white to black
Create RootViewController
Add an UIView to RootViewController
Add an UIButton as type is Info Light
Connect RootViewController to outlet as rootViewController
Create a button’s property as infoButton
Create MainViewController with XIB
Add an UIView and UILable
Override dealloc method
Create an outlet for digital clock display
Create a property alarmOn
Create a timer and display current time to digital clock label
Change attribute of property from strong to retain because using non-ARC
Update views
Shows sub views