[iOS] How to change Status Bar Style in iOS 7 / 8

In Info.plist set 'View controller-based status bar appearance' as NO

In AppDelegate add

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
   [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];

}

Reference : 
http://stackoverflow.com/questions/17678881/how-to-change-status-bar-text-color-in-ios-7