Examine source code of Hourglass in seconds

{
  "name": "Hourglass in seconds",
  "manifest_version": 3,
  "version": "1.6.2",
  "description": "Hourglass enhanced",
  "author": "Sam Kauffman (SamVK)",
  "icons": {
    "16": "img/icon/icon-16.png",
    "48": "img/icon/icon-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6bbb52fc-716d-46f7-99d7-57a1d71357f3}"
    }
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://sec.kmbs.us/version2/lab/hourglass/*"
      ],
      "css": [
        "style.css",
        "changelog-alert/style.css"
      ],
      "js": [
        "utils.js",
        "storage.js",
        "changelog-alert/index.js"
      ]
    },
    {
      "matches": [
        "https://sec.kmbs.us/version2/lab/hourglass/activity.html*"
      ],
      "js": [
        "add-new-activity.js"
      ]
    },
    {
      "matches": [
        "https://sec.kmbs.us/version2/lab/hourglass/home.html*"
      ],
      "js": [
        "default-button.js",
        "add-summer-hours.js",
        "add-templates.js",
        "delete-activity.js"
      ]
    }
  ]
}