Examine source code of Plan - Calendar & Tasks

{
  "author": "Plan Inc.",
  "background": {
    "persistent": false,
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "16": "images/logo-16x16.png",
      "32": "images/logo-32x32.png",
      "48": "images/logo-48x48.png",
      "128": "images/logo-128x128.png"
    },
    "default_title": "Open Plan"
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "content_security_policy": "script-src 'self' https://ssl.google-analytics.com; object-src 'self'",
  "description": "The beautiful new tab page with your calendars and tasks.",
  "host_permissions": [
    "https://*.getplan.co/"
  ],
  "icons": {
    "16": "images/logo-16x16.png",
    "32": "images/logo-32x32.png",
    "48": "images/logo-48x48.png",
    "128": "images/logo-128x128.png"
  },
  "manifest_version": 2,
  "name": "Plan - Calendar & Tasks",
  "optional_permissions": [
    "geolocation"
  ],
  "permissions": [
    "storage"
  ],
  "short_name": "Plan",
  "version": "1.3.1",
  "web_accessible_resources": [
    "fonts/*.ttf",
    "fonts/*.otf",
    "fonts/*.eot",
    "fonts/*.woff",
    "fonts/*.jpeg",
    "*.svg"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{a19a9331-0c33-4692-accf-9b1a4fa17482}"
    }
  }
}