Examine source code of Classroomtils

{
  "manifest_version": 2,
  "name": "Classroomtils",
  "version": "1.0",
  "description": "Bunch of utilities for Google Classroom",
  "icons": {
    "48": "icons/48.png",
    "96": "icons/96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://classroom.google.com/u/*/h",
        "https://classroom.google.com/u/*/"
      ],
      "js": [
        "classroom.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{25481661-d57b-450d-bae3-28627c6eedd3}"
    }
  }
}