Examine source code of Image Click Downloader

{
  "manifest_version": 2,
  "name": "Image Click Downloader",
  "version": "1.3",
  "default_locale": "en",
  "description": "__MSG_extensionDescription__",
  "applications": {
    "gecko": {
      "id": "addon_image_click_downloader@forest-soft.net"
    }
  },
  "icons": {
    "48": "icons/icon-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*",
        "file://*/*"
      ],
      "js": [
        "main.js"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options_ui/options.html"
  },
  "permissions": [
    "downloads",
    "notifications",
    "storage",
    "<all_urls>"
  ],
  "optional_permissions": []
}