Examine source code of Smart Tab Manager

{
  "manifest_version": 2,
  "name": "Smart Tab Manager",
  "version": "1.0",
  "description": "Automatically group related tabs.",
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icon.png"
    }
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8dde4868-a46a-460a-87a9-2c5739702324}"
    }
  }
}