Examine source code of Text Transformer Plus

{
  "manifest_version": 2,
  "name": "Text Transformer Plus",
  "version": "1.0",
  "description": "Converts text case and provides additional text transformation tools",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f906feb6-778b-4660-a75c-e22462be35f1}"
    }
  }
}