Examine source code of Simple Tab Rename

{
  "name": "Simple Tab Rename",
  "version": "1.0",
  "description": "Change the title of single or multiple tabs in an easy way. New title stays even after refresh",
  "manifest_version": 2,
  "permissions": [
    "tabs",
    "activeTab",
    "notifications",
    "http://*/",
    "https://*/"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Rename tabs",
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon48_48.png",
      "128": "icon128_3.png"
    }
  },
  "icons": {
    "48": "icon48_48.png",
    "128": "icon128_3.png"
  }
}