UIApplication is a singleton object that represents the application.
Parameters for UIKit applications
UIApplicationMain recognizes the following these special flags:
| Flag | Purpose |
|---|---|
| -BuildDefaultPNG | Write the default PNG image to ~/Library/Caches/AppSnapshots/BundleID.png (by calling -[UIApplication _writeApplicationDefaultPNGSnapshot] on start up). |
| -RegisterForSystemEvents | Allow this app to receive system events which normally should be received by SpringBoard. |