One of the ObjC examples could be more concise. He writes:

  id navigationBar = [UINavigationBar appearance];
  [navigationBar setBackgroundImage:[UIImage imageNamed:@"nav-background.png"] forBarMetrics:UIBarMetricsDefault];
  [navigationBar setTitleTextAttributes:[[NSDictionary alloc] initWithObjectsAndKeys:
    [UIFont cheddarFontWithSize:24.0f], UITextAttributeFont,
    [UIColor colorWithWhite:0.0f alpha:0.4f], UITextAttributeTextShadowColor,
    [UIColor whiteColor], UITextAttributeTextColor,
    nil]];

which could be

  id navigationBar = [UINavigationBar appearance];
  [navigationBar setBackgroundImage:[UIImage imageNamed:@"nav-background.png"] forBarMetrics:UIBarMetricsDefault];
  [navigationBar setTitleTextAttributes:@{
    UITextAttributeFont : [UIFont cheddarFontWithSize:24],
    UITextAttributeTextShadowColor : [UIColor colorWithWhite:0 alpha:0.4],
    UITextAttributeTextColor : [UIColor whiteColor],
  }];

as compares to the Ruby,

  navigationBar = UINavigationBar.appearance
  navigationBar.setBackgroundImage(UIImage.imageNamed('nav-background.png'), forBarMetrics: UIBarMetricsDefault)
  navigationBar.setTitleTextAttributes({
    UITextAttributeFont: UIFont.cheddarFontWithSize(24.0),
    UITextAttributeTextShadowColor: UIColor.colorWithWhite(0.0, alpha:0.4),
    UITextAttributeTextColor: UIColor.whiteColor
  })

Also kind of wondering where he got "cheddarFont". :-)