Examine source code of Hide Scores Tool

{
  "manifest_version": 2,
  "name": "Hide Scores Tool",
  "version": "1.0",
  "description": "Hides scores and ratings on supported websites until you hover over them.",
  "permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.example-website.com/*"
      ],
      "js": [
        "content-script.js"
      ],
      "css": [
        "style.css"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6df8b18a-e6f6-49b7-8fc4-f38f59a078b5}"
    }
  }
}