Examine source code of Serene - New Tab

{
  "short_name": "Serene",
  "name": "Serene",
  "browser_action": {
    "default_popup": "index.html",
    "default_title": "Serene"
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "author": "Tanay Joshi",
  "version": "1.0",
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{14c462e7-7cf9-4b60-98a8-0cb829b8e183}"
    }
  }
}