Examine source code of Bitly URL Shortner

{
  "manifest_version": 2,
  "name": "Bitly URL Shortner",
  "short_name": "Bitly URL Shortner",
  "version": "1.0.0",
  "description": "Bitly service to convert long URLs or Links of websites to short.",
  "icons": {
    "16": "img/icon16.png",
    "48": "img/icon48.png",
    "128": "img/icon128.png"
  },
  "background": {
    "page": "background.html"
  },
  "browser_action": {
    "default_icon": "img/icon128.png",
    "default_title": "Bitly URL Shortner",
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab",
    "contextMenus"
  ]
}