Examine source code of Email Manager

{
  "manifest_version": 2,
  "name": "Email Manager",
  "version": "1.0",
  "description": "Manage and track emails from multiple accounts.",
  "permissions": [
    "storage",
    "notifications",
    "https://mail.google.com/",
    "https://outlook.live.com/"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "32": "icons/logo_32.png",
      "64": "icons/logo_64.png",
      "128": "icons/logo_128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "32": "icons/logo_32.png",
    "64": "icons/logo_64.png",
    "128": "icons/logo_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ce744ef1-59ff-4adf-bf6e-17b5529ca4a2}"
    }
  }
}