Examine source code of Page Word Cloud

{
  "manifest_version": 2,
  "name": "Page Word Cloud",
  "version": "1.0",
  "description": "Generate a word cloud of the most frequent words on any webpage, displayed with font sizes proportional to frequency in a deep purple interface.",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4bc27cc0-7861-40e0-a83e-7e6ae8f2598c}"
    }
  }
}