Examine source code of Distraction Curtain

{
  "manifest_version": 2,
  "name": "Distraction Curtain Pro",
  "version": "2.3.2",
  "description": "Draw curtains to block distractions. Upgrade to Pro for per-site memory and resize handles.",
  "permissions": [
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon.png",
      "48": "icon.png",
      "128": "icon.png"
    }
  },
  "icons": {
    "16": "icon.png",
    "48": "icon.png",
    "128": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "content_script.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "distraction-curtain-new@extensionandapps.com",
      "strict_min_version": "109.0"
    }
  }
}