Examine source code of Classroom Tools

{
  "manifest_version": 2,
  "name": "Classroom Tools",
  "version": "0.0.3",
  "description": "A presentation tool for masking and unveiling, basic text editing, and hiding sections of a webpage.",
  "homepage_url": "https://broadervisions.co.uk/teaching/browser-extension-whiteboard-page-mask-for-teachers/",
  "icons": {
    "16": "icons/ext-icon-16.png",
    "32": "icons/ext-icon-32.png",
    "48": "icons/ext-icon-48.png",
    "64": "icons/ext-icon-64.png",
    "128": "icons/ext-icon-128.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "web_accessible_resources": [
    "image/*.png"
  ],
  "browser_action": {
    "browser_style": true,
    "default_popup": "main.html",
    "default_icon": "icons/ext-icon-64.png",
    "default_title": "Classroom Tools"
  }
}