Examine source code of showHTML

{
  "manifest_version": 2,
  "name": "showHTML",
  "description": "See details about a web page's HTML elements as you hover over them.",
  "version": "1.0.2resigned1",
  "short_name": "Show HTML tag names, IDs & classes for a web page",
  "homepage_url": "http://tech-in-check.blogspot.com/p/showhtml.html",
  "author": "freginold",
  "icons": {
    "16": "showHTML16.png",
    "32": "showHTML32.png",
    "48": "showHTML48.png",
    "64": "showHTML64.png",
    "96": "showHTML96.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "showHTML16.png",
      "32": "showHTML32.png",
      "48": "showHTML48.png",
      "64": "showHTML64.png",
      "96": "showHTML96.png"
    },
    "default_title": "showHTML",
    "browser_style": true
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "options_ui": {
    "page": "options.html",
    "chrome_style": true
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "applications": {
    "gecko": {
      "id": "showHTMLff@addon.org"
    }
  }
}