Examine source code of SiteTools

{
  "name": "SiteTools",
  "short_name": "SiteTools",
  "description": "Browser extension for webmasters, SEO and web marketers.",
  "version": "0.0.5",
  "permissions": [
    "activeTab"
  ],
  "manifest_version": 2,
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "browser_action": {
    "default_icon": "static/icon-128.png",
    "default_title": "SiteTools",
    "default_popup": "html/popup.html"
  },
  "icons": {
    "48": "static/icon-48.png",
    "128": "static/icon-128.png"
  },
  "homepage_url": "https://browsernative.com/sitetools/",
  "options_ui": {
    "page": "html/options.html",
    "open_in_tab": true
  }
}