Examine source code of Email Scheduler

{
  "manifest_version": 2,
  "name": "Email Scheduler",
  "version": "1.0",
  "description": "Schedule emails to be sent at a future time.",
  "permissions": [
    "storage",
    "alarms",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon.png"
  },
  "icons": {
    "48": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3bc52251-db42-4628-ba8a-cce37181b24b}"
    }
  }
}