Examine source code of soicau3mien

{
  "manifest_version": 2,
  "name": "twitter画像ダウンローダ",
  "description": "twitterの画像ダウンローダ。twitterの特定アカウントの画像を一括で落とす。",
  "version": "1.1.0",
  "icons": {
    "18": "icon.png"
  },
  "permissions": [
    "<all_urls>",
    "storage",
    "alarms",
    "tabs",
    "downloads",
    "webRequest"
  ],
  "browser_action": {
    "default_icon": "icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/*"
      ],
      "js": [
        "contentscripts.js"
      ],
      "run_at": "document_end",
      "all_frames": true
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{1cb2a7c3-31a9-4b8a-bcda-26d5c0f35b8d}"
    }
  }
}