Examine source code of Megafile

{
  "manifest_version": 2,
  "name": "Megafile",
  "description": "Pobieranie plików bezpośrednio z poziomu przeglądarki!",
  "version": "1.0.2resigned1",
  "browser_action": {
    "default_icon": "data/images/icon.png",
    "default_popup": "data/html/login.html"
  },
  "icons": {
    "16": "data/images/icon.png",
    "48": "data/images/icon48.png",
    "128": "data/images/icon128.png"
  },
  "background": {
    "scripts": [
      "data/vendor/jquery-3.1.0.min.js",
      "data/js/helperFunctions.js",
      "data/js/onBrowserStartEvents.js",
      "data/js/contextMenu.js"
    ]
  },
  "content_scripts": [
    {
      "js": [
        "data/vendor/jquery-3.1.0.min.js",
        "data/js/content_scripts.js"
      ],
      "matches": [
        "*://*/*"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "*://*/*",
    "tabs",
    "contextMenus",
    "notifications",
    "storage",
    "downloads",
    "https://*.megafile.pl/"
  ],
  "web_accessible_resources": [
    "data/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f245d8bd-04cb-416f-8b7d-6fc17245c806}"
    }
  }
}