Examine source code of Highlight Fields v1.1

{
  "manifest_version": 2,
  "name": "Highlight Fields",
  "version": "1.1",
  "description": "Highlight all fields on the page, including hidden ones.",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "style.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{3dd20323-f692-4691-b9e0-5ca0fd71264e}"
    }
  }
}