Examine source code of AiK Seo bar

{
  "description": "An webextension for basic SEO needs. Russian interface only.",
  "manifest_version": 2,
  "name": "AiK SEO bar",
  "author": "Artyem V Shkondin",
  "version": "0.2.1",
  "homepage_url": "http://www.shkondin.ru/seobar",
  "background": {
    "scripts": [
      "seobar.js"
    ]
  },
  "icons": {
    "48": "icons/seobar_icon_48.png"
  },
  "page_action": {
    "browser_style": false,
    "default_icon": {
      "16": "icons/pageinfo.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/**"
      ],
      "css": [
        "noindex.css"
      ]
    }
  ],
  "permissions": [
    "tabs"
  ]
}