Examine source code of Commitment Timer

{
  "manifest_version": 2,
  "name": "Commitment Timer",
  "version": "1.0.0",
  "description": "Force yourself to commit before visiting distracting sites.",
  "browser_specific_settings": {
    "gecko": {
      "id": "commitment-timer@ringku",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "webNavigation",
    "storage",
    "alarms",
    "tabs",
    "notifications",
    "*://*.youtube.com/*",
    "*://*.reddit.com/*",
    "*://*.twitter.com/*",
    "*://*.instagram.com/*",
    "*://*.tiktok.com/*",
    "*://*.facebook.com/*",
    "*://*.x.com/*",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "browser-polyfill.js",
      "background/service-worker-firefox.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "assets/icon16.png",
      "48": "assets/icon48.png",
      "128": "assets/icon128.png"
    }
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "icons": {
    "16": "assets/icon16.png",
    "48": "assets/icon48.png",
    "128": "assets/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*",
        "*://*.reddit.com/*",
        "*://*.twitter.com/*",
        "*://*.instagram.com/*",
        "*://*.tiktok.com/*",
        "*://*.facebook.com/*",
        "*://*.x.com/*"
      ],
      "js": [
        "browser-polyfill.js"
      ],
      "run_at": "document_start"
    }
  ],
  "web_accessible_resources": [
    "browser-polyfill.js"
  ]
}