Examine source code of Inspect Duplicate Tabs

{
  "author": "igorlogius",
  "homepage_url": "https://github.com/igorlogius/inspect-duplicate-tabs",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_area": "navbar"
  },
  "icons": {
    "256": "icon.png"
  },
  "manifest_version": 2,
  "name": "Inspect Duplicate Tabs",
  "permissions": [
    "tabs"
  ],
  "version": "1.0.1",
  "browser_specific_settings": {
    "gecko": {
      "id": "{7065d18f-9320-4df4-832a-f73b113484a2}"
    }
  }
}