ios access main window or view

I would like to know if there is a simple way to access the main window or view in IOS. Something similar to:

[UIScreen mainScreen]

Thank you.

Try :

UIWindow *frontWindow = [[[UIApplication sharedApplication] windows]
                                                            lastObject];

or simply :

UIWindow *frontWindow = [[UIApplication sharedApplication] keyWindow];

The main window is best found using UIWindow * mainWindow = [UIApplication sharedApplication].windows.firstObject;

Using keyWindow can return a keyboard or UIAlertView window, which lie above your application window.

If you have a pointer to some subview in the window, you can easily access its window:

UIWindow *window = mySubview.window;

Simply clever, works from any class:

[(YourAppDelegate *)[[UIApplication sharedApplication] delegate] window];

Note: don't forget to import your appDelegate class