Place this snippet in the view controller (MainViewController, ChildBrowserViewController, etc) to push the view down 20px to account for the transparent iOS 7 status bar.

phonegap-ios-7-status-bar-fix.m

@implementation MainViewController

- (void)viewWillAppear:(BOOL)animated
{
    // Lower screen 20px on iOS 7
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7) {
        CGRect viewBounds = [self.view bounds];
        viewBounds.origin.y = 20;
        viewBounds.size.height = viewBounds.size.height - 20;
        self.webView.frame = viewBounds;
    }
    
    [super viewWillAppear:animated];
}
- (void)viewDidLoad
{
    [super viewDidLoad];
    
    // Lower screen 20px on iOS 7
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7) {
        CGRect viewBounds = [self.view bounds];
        viewBounds.origin.y = 20;
        viewBounds.size.height = viewBounds.size.height - 20; // Push view down 20px to accomidate for iOS 7 status bar
        self.webView.frame = viewBounds;
    }
    
    // Set bg color to black
    self.view.backgroundColor = [UIColor blackColor]; 
    
}
// Set text color in status bar to white
-(UIStatusBarStyle)preferredStatusBarStyle{
    return UIStatusBarStyleLightContent; 
}

@end

Setting the Status Bar background color to a custom color or a color matching your theme
Instead of the default colors you able to define your own using RGB values.
Ex. self.view.backgroundColor = [UIColor colorWithRed:0/255.0f green:8/255.0f blue:36/255.0f alpha:1.0f];
UIColor Code Generator allows you to select your own color while generating the iOS code for you.