Examine source code of TimetableForWeb

{
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "TimetableForWeb@Sungho.Hwang",
      "strict_min_version": "78.0"
    }
  },
  "name": "TimetableForWeb",
  "version": "34.1",
  "description": "Simple timetable for web.",
  "icons": {
    "32": "tt32.png"
  },
  "browser_action": {
    "default_icon": "tt32.png",
    "default_title": "TimetableForWeb"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}