Examine source code of SubeDown

{
  "manifest_version": 2,
  "name": "SubeDown",
  "version": "1.8",
  "description": "Download images and videos from web pages",
  "permissions": [
    "downloads",
    "activeTab",
    "tabs",
    "scripting",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "browser_action": {
    "default_title": "SubeDown",
    "default_popup": "sidebar.html"
  },
  "background": {
    "scripts": [
      "./util/clean-url.js",
      "./util/image-util.js",
      "./util/network.js",
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "./util/clean-url.js",
        "./util/image-util.js",
        "content_script.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "sidebar_action": {
    "default_title": "SubeDown",
    "default_panel": "sidebar.html",
    "default_icon": {
      "16": "./images/icon-16.png",
      "32": "./images/icon-32.png",
      "48": "./images/icon-48.png",
      "128": "./images/icon-128.png"
    }
  },
  "icons": {
    "16": "./images/icon-16.png",
    "32": "./images/icon-32.png",
    "48": "./images/icon-48.png",
    "128": "./images/icon-128.png"
  },
  "web_accessible_resources": [
    "sidebar.html",
    "sidebar.css",
    "./util/clean-url.js",
    "./util/network.js",
    "sidebar.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f294fa84-28e3-4c96-870d-e435c712c8fd}"
    }
  }
}