Examine source code of ImageFocusGuard

{
  "manifest_version": 2,
  "name": "ImageFocusGuard",
  "version": "1.0",
  "description": "Blur all images on the page except the one you're hovering over to help focus.",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "style.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f1c082cc-28ba-43f7-8eee-8575776b70c9}"
    }
  }
}