iOS -- Things I Forget

The App Icon of an iPad Application is 72x72 pixels.
Get all icon sizes here and advice here.

Remove the shine effect from the iPad App Icon:
Info.plist > Open As > Source Code

<key>UIPrerenderedIcon</key>

<true/>

Run your App only in landscape mode:
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{ return (interfaceOrientation == UIInterfaceOrientationLandscapeLeft); }

Remove the Status Bar
Info.plist > Open As > Source Code:

<key>UIStatusBarHidden</key>

<true/>

To add a background image to your application, do the following in your AppDelegate didFinishLaunching, where wall1.png is a 1024x760 vertical wallpaper, and mainView is your view controller.
self.window.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"wall1.png"]];
self.mainView.view.backgroundColor = [UIColor clearColor];

Custom Fonts:
It seems you can only customize the font of your labels programatically. See Creating a UILabel programmatically for some sample code that you could drop in your viewDidLoad

Iterate (for loop) over a string array:
NSArray * words = [NSArray arrayWithObjects:@"one",@"two",@"three",nil];
for(NSString * str in words) {
    NSLog(@"%@",str);
}

Static UIColor
...