title: Manifest Validates but App Opens with Blank Screen?
body: <p>I'm adding a manifest to my web app for the first time. My manifest validates successfully at manifest-validator.appspot.com. And the Chrome Application->Service Worker window shows the service worker as successfully registered. I am able to "Save to Home Screen" on my iPhone. But when I open the icon saved to the home screen, I get a blank screen.</p>
  
  <p>Here's my myApp_manifest.json file:</p>
  
  <pre><code>{
    "short_name": "myApp",
    "name": "myAppLongName",
    "icons": [
      {
        "src": "images/app-images/myIcon-512-green_512px.png",
        "type": "image/png",
        "sizes": "512x512"
      },
      {
        "src": "images/app-images/myIcon-512-green_192px.png",
        "type": "image/png",
        "sizes": "192x192"
      }
    ],
    "start_url": "/?utm_source=progressive_web_app",
    "background_color": "#63aed5",
    "display": "standalone",
    "scope": "/",
    "theme_color": "#3367D6"
  }
  </code></pre>
  
  <p>What am I missing?</p>