Examine source code of Byebook

{
  "manifest_version": 2,
  "name": "Byebook",
  "version": "1.1resigned1",
  "content_scripts": [
    {
      "matches": [
        "https://www.facebook.com/*"
      ],
      "js": [
        "page-eater.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{834f932d-b765-4042-83cd-afe2e7f6b63c}"
    }
  }
}