Examine source code of OGraph Previewer

{
  "name": "OGraph Previewer",
  "version": "2.0.0",
  "manifest_version": 2,
  "description": "A light-weight extension to preview the open graph tags (og tags) of the page in your current tab",
  "author": "Parthipan Natkunam",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "scripting",
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/icon19.png",
    "default_title": "oGraph Previewer",
    "default_popup": "browser_action.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{76d4f898-db27-4e9a-9ae7-e7b14e250ff8}"
    }
  }
}