Examine source code of New app icon

{
  "manifest_version": 2,
  "name": "New app icon",
  "version": "1.0",
  "description": "A new app icon is used to attract users' attention to an app that has just been released, or has just been uploaded to the app store. It helps the app stand out among thousands of other apps.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Click me!"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{427a4492-3061-4b76-a8f9-eb0394104cc0}"
    }
  }
}