Examine source code of OpenRefine Companion

{
  "manifest_version": 2,
  "name": "OpenRefine Companion",
  "version": "1.0",
  "description": "Quick access to your local OpenRefine instance.",
  "icons": {
    "48": "icons/icon.png"
  },
  "browser_action": {
    "default_icon": "icons/icon.png",
    "default_popup": "popup.html",
    "default_title": "Open OpenRefine"
  },
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4372bc78-ec08-44c9-8ebd-6696a52ef2d8}"
    }
  }
}