A vanilla JS implementation for http://blog.imusr.de/codeschnipsel-ios-version-abhaengige-statusbar-via-jquery/

gistfile1.js

// Check iOS Version and change the META
window.onload = function() {
  var iOSVersion;
  if (/iP(hone|od|ad)/.test(navigator.platform)) {
    // supports iOS 2.0 and later
    var v = (navigator.appVersion).match(/OS (\d+)_(\d+)_?(\d+)?/);
    iOSVersion = [parseInt(v[1], 10), parseInt(v[2], 10), parseInt(v[3] || 0, 10)];
    iOSVersion = parseInt(iOSVersion[0]);
  }

  if (iOSVersion >= 7) {
    color = 'black-translucent';
  } else {
    color = 'black';
  }
  
  // Create a new element
  tag = document.createElement('meta');
  tag.name = 'apple-mobile-web-app-status-bar-style';
  tag.content = color;

  document.getElementsByTagName('head')[0].appendChild(tag);
};