Examine source code of Stackalyzer

{
  "applications": {
    "gecko": {
      "id": "prestastackalyzer@gmail.com",
      "strict_min_version": "55.0"
    }
  },
  "name": "Stackalyzer",
  "version": "1.0",
  "description": "Search stack used for the website you look",
  "icons": {
    "16": "images/icon.16.png",
    "32": "images/icon.32.png",
    "48": "images/icon.48.png",
    "128": "images/icon.128.png"
  },
  "permissions": [
    "tabs",
    "activeTab",
    "cookies",
    "*://*/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start",
      "css": [],
      "js": [
        "js/content.js"
      ]
    }
  ],
  "background": {
    "page": "background.html"
  },
  "browser_action": {
    "default_icon": {
      "16": "images/icon.16.png",
      "32": "images/icon.32.png"
    },
    "default_popup": "popup.html",
    "default_title": "Stackalyzer"
  },
  "manifest_version": 2,
  "web_accessible_resources": [
    "js/inject.js"
  ]
}