Examine source code of Instabook

{
  "manifest_version": 2,
  "name": "Instabook",
  "version": "1.2.11",
  "author": "Bartosz Wójcik",
  "homepage_url": "https://github.com/bartoffw/instabook",
  "description": "Create an eBook from any page instantly and beautifully.",
  "icons": {
    "48": "icons/logo-48.png",
    "96": "icons/logo-96.png"
  },
  "background": {
    "scripts": [
      "scripts/jquery.min.js",
      "scripts/Readability.js",
      "scripts/jszip-utils.min.js",
      "scripts/purify.js",
      "scripts/filesaver.min.js",
      "scripts/jszip.min.js",
      "scripts/storage.js",
      "scripts/epub.js",
      "scripts/background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "scripts/jquery.min.js",
        "scripts/jszip-utils.min.js",
        "scripts/purify.js",
        "scripts/Readability.js",
        "scripts/epub.js",
        "scripts/content_script.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "assets/cover.jpg",
    "assets/divider.png"
  ],
  "permissions": [
    "activeTab",
    "storage",
    "unlimitedStorage"
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/logo-16.png",
      "32": "icons/logo-32.png"
    },
    "default_title": "Instabook It!",
    "default_popup": "action/popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{bf26f300-657d-45f4-a55d-fb7f4749fb75}"
    }
  }
}