Examine source code of Clippy

{
  "manifest_version": 2,
  "name": "Clippy",
  "short_name": "Clippy Assistant",
  "description": "Clippy MS Word Office assistant is now back to assist inside your browser!",
  "version": "1.9.2",
  "author": "Ante Barić (capJavert)",
  "icons": {
    "16": "assets/img/clippy-icon-16x16.png",
    "48": "assets/img/clippy-icon-48x48.png",
    "128": "assets/img/clippy-icon-128x128.png"
  },
  "browser_action": {
    "default_title": "Clippy Assistant",
    "default_icon": {
      "16": "assets/img/clippy-icon-gray-48x48.png",
      "24": "assets/img/clippy-icon-gray-48x48.png",
      "32": "assets/img/clippy-icon-gray-48x48.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "assets/css/clippy.css"
      ],
      "js": [
        "assets/js/jquery.min.js",
        "assets/js/clippy.js",
        "assets/js/agent.js",
        "lib/index.js"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "assets/js/web-storage-object.js",
      "lib/state.js"
    ],
    "persistent": true
  },
  "web_accessible_resources": [
    "assets/img/clippy.map.png"
  ],
  "permissions": [
    "activeTab",
    "https://clippy-dictionary.kickass.website/*"
  ],
  "externally_connectable": {
    "matches": [
      "http://localhost:8080/*",
      "https://capjavert.github.com/*",
      "https://antebaric.from.hr/*",
      "http://antebaric.from.hr/*",
      "https://kickass.website/*",
      "https://clippy.kickass.website/*",
      "https://*.capjavert.now.sh/*"
    ]
  }
}