Examine source code of Interface Cleaner Plus+

{
  "manifest_version": 2,
  "name": "Interface Cleaner",
  "version": "1.0",
  "description": "Streamline your browsing experience by removing unwanted content like ads and distractions from websites, leaving you with a clean and focused interface",
  "icons": {
    "48": "images/duckduckgo-focus.48.png",
    "512": "images/duckduckgo-focus.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.duckduckgo.com/*"
      ],
      "js": [
        "ddg-focus.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8e24ab03-6aaa-4d75-88c1-a11587f636c0}"
    }
  }
}