Examine source code of Panic Button

{
  "manifest_version": 2,
  "name": "Panic Button",
  "description": "This extension allows user to close all opened tabs with s single button click. Allows to set a webpage to open.",
  "version": "1.1",
  "background": {
    "scripts": [
      "back.js"
    ]
  },
  "icons": {
    "128": "icon128.png"
  },
  "browser_action": {
    "default_icon": "icon.png"
  },
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "permissions": [
    "tabs",
    "storage"
  ]
}