Examine source code of TabuRei

{
  "description": "Cross Browser Extension to manage your tabs",
  "manifest_version": 2,
  "name": "TabuRei",
  "version": "0.7.2",
  "homepage_url": "https://github.com/osdc/TabuRei",
  "icons": {
    "48": "icons/icon-48.png"
  },
  "permissions": [
    "tabs",
    "storage",
    "cookies"
  ],
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "Taburei",
    "default_popup": "popup.html"
  }
}