Examine source code of Kingvoice

{
  "name": "Kingvoice",
  "manifest_version": 2,
  "version": "2.0.0",
  "description": "Extensão para integrações com o PABX-IP IPix da Kingvoice",
  "icons": {
    "16": "img/icon_016.png",
    "32": "img/icon_032.png",
    "48": "img/icon_048.png",
    "128": "img/icon_128.png"
  },
  "browser_action": {
    "default_icon": "img/icon_032.png",
    "default_title": "Virtualfone - Kingvoice",
    "default_popup": "popup/index.html"
  },
  "options_ui": {
    "page": "index.html"
  },
  "background": {
    "scripts": [
      "background/listener.js",
      "background/background.js",
      "background/acoes.js"
    ]
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "*://*.google.com/*",
        "*://*.lightning.force.com/*",
        "*://*.zendesk.com/*",
        "*://*.desk.ms/*"
      ],
      "js": [
        "content/principal.js",
        "content/google.js",
        "content/zendesk.js",
        "content/salesforce.js"
      ]
    }
  ],
  "permissions": [
    "tabs",
    "notifications",
    "storage"
  ]
}