Examine source code of appear1

{
  "name": "Appear1画面共有ライブラリ",
  "short_name": "appear1",
  "version": "0.0.3resigned1",
  "manifest_version": 2,
  "description": "Appear1画面共有ライブラリです。",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "permissions": [
    "desktopCapture",
    "tabs",
    "https://appear1.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "https://appear1.com/*"
      ],
      "js": [
        "content.js"
      ],
      "all_frames": true,
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{5f2ae6d9-6e32-48e8-86df-6ebf30cf421c}"
    }
  }
}