Examine source code of Prembox.com

{
  "manifest_version": 2,
  "name": "Prembox.com",
  "version": "2.0.1resigned1",
  "default_locale": "en",
  "description": "__MSG_extensionDescription__",
  "homepage_url": "https://prembox.com",
  "icons": {
    "48": "icons/logotype-48.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "cookies",
    "contextMenus",
    "webRequest",
    "notifications",
    "http://prembox/*",
    "https://prembox/*",
    "http://*.prembox.com/*",
    "https://*.prembox.com/*",
    "https://prembox.com/*"
  ],
  "browser_action": {
    "browser_style": false,
    "default_icon": "icons/logotype-48.png",
    "default_title": "Prembox",
    "default_popup": "popup/main.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "thirdparty/browser-polyfill.min.js",
        "content/filehostpage.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "thirdparty/browser-polyfill.min.js",
      "thirdparty/jquery-3.2.0.min.js",
      "background/utils_bg.js",
      "background/api.js",
      "background/context_menu.js",
      "background/filehost.js"
    ]
  },
  "web_accessible_resources": [
    "images/logo.png"
  ],
  "options_ui": {
    "page": "settings/options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{edb07fe7-3b8f-46c8-b461-f18cf2c9096d}"
    }
  }
}