Examine source code of TinyURL Pro

{
  "manifest_version": 2,
  "name": "TinyURL Pro",
  "short_name": "TinyURL Shortener",
  "version": "1.0.8",
  "description": "TinyURL - Convert long website links to short",
  "icons": {
    "16": "img/icon16.png",
    "48": "img/icon48.png",
    "128": "img/icon128.png"
  },
  "browser_action": {
    "default_icon": "img/icon128.png",
    "default_title": "TinyURL - URL Shortener",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "storage"
  ]
}