manifest.json

{
   "name": "WhatsApp Online Tracker",
   "version": "0.1",
   "description": "A google chrome  extension to track when people online and offline on WhatsApp!",
   "permissions": ["activeTab", "declarativeContent", "storage"],
   "background": {
      "scripts": ["background.js"],
      "persistent": true
   },
   "page_action": {
      "default_popup": "popup.html",
      "default_icon": {
         "16": "images/icon_16.png",
         "32": "images/icon_32.png",
         "48": "images/icon_48.png",
         "128": "images/icon_128.png"
     }
   },
   "options_page": "options.html",
   "icons": {
      "16": "images/icon_16.png",
      "32": "images/icon_32.png",
      "48": "images/icon_48.png",
      "128": "images/icon_128.png"
   },
   "manifest_version": 2
}