Examine source code of InsertLearning Advanced

{
  "manifest_version": 2,
  "name": "InsertLearning",
  "description": "Insert instructional content on any web page",
  "version": "2.2.0",
  "icons": {
    "128": "lib/img/icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://docentedu.com/*",
        "https://insertlearning.com/*",
        "https://www.okeebo.com/*"
      ],
      "js": [
        "version.js"
      ],
      "all_frames": true
    },
    {
      "matches": [
        "https://insertlearning.com/v1/share/*"
      ],
      "js": [
        "share.js"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "https://insertlearning.com/v1/lesson/*"
      ],
      "js": [
        "lesson.js"
      ],
      "all_frames": true,
      "run_at": "document_end"
    }
  ],
  "browser_action": {
    "default_title": "InsertLearning",
    "default_icon": "lib/img/icon.png"
  },
  "permissions": [
    "activeTab",
    "scripting",
    "storage",
    "webNavigation"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "optional_permissions": [
    "identity"
  ],
  "web_accessible_resources": [
    "lib/fonts/*",
    "lib/iframe/*",
    "lib/img/*"
  ],
  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAx77dY6nQKrjpTulS2r/78MgizLQbjonZBoL/CQy2/IuLEYviiW23gk9xK8Ba8N/v7x2C1WcqrkZSVgtqsoSbYt5XoOvPAMZLcS3REvFJGCsrtGrndnoX0bFdZVrlIPDVvHIcRsjnDFYWC8SoWaDEuTAWi+PTcjck8dZ+69Q8S9lHotgh01KxFJtxwxi8PNF4koUREPKOcsopq0OC8MJH9foIGCSmyzz6wiiozCD8ryhV6EM8JqhQ7+MsnHMzv5rJfw+g8ZKDDH/ZM/uM3skmOAJF1e9lfX21X6UFYjHzVUoYH+c4Xosx3XCLgBIcyyTSyas+cZtBptcUtJDFEdLNuQIDAQAB",
  "browser_specific_settings": {
    "gecko": {
      "id": "{79f7289c-f870-4bf1-9558-96e208eba20e}"
    }
  }
}