Examine source code of PublishWide Sync

{
  "manifest_version": 2,
  "name": "PublishWide Sync",
  "description": "PublishWide Sync Extension",
  "version": "2.9.2.10",
  "browser_action": {
    "default_icon": "icon.png"
  },
  "background": {
    "scripts": [
      "vendor.js",
      "background.js"
    ]
  },
  "permissions": [
    "storage",
    "tabs",
    "webRequest",
    "webRequestBlocking",
    "extraHeaders",
    "https://*.publishwide.com/*",
    "https://kdp.amazon.com/*",
    "https://account.kdp.amazon.com/*",
    "https://kdpreports.amazon.com/*",
    "https://amazon.com/*",
    "https://www.amazon.com/*",
    "https://advertising.amazon.com/*",
    "https://advertising.amazon.co.uk/*",
    "https://advertising.amazon.de/*",
    "https://advertising.amazon.fr/*",
    "https://advertising.amazon.es/*",
    "https://advertising.amazon.it/*",
    "https://advertising.amazon.co.jp/*",
    "https://advertising.amazon.in/*",
    "https://advertising.amazon.ca/*",
    "https://advertising.amazon.com.mx/*",
    "https://advertising.amazon.com.au/*",
    "https://press.barnesandnoble.com/*",
    "https://itunesconnect.apple.com/*",
    "https://uclient-api.itunes.apple.com/*",
    "https://www.draft2digital.com/*",
    "https://play.google.com/*",
    "https://writinglife.kobo.com/*",
    "https://*.smashwords.com/*",
    "https://*.acx.com/*",
    "https://*.radishfiction.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{bc444522-2a95-4139-83b9-5caf34834611}"
    }
  }
}