countdown-command.json

{
  "type": "APL",
  "version": "1.3",
  "settings": {},
  "theme": "dark",
  "import": [],
  "resources": [],
  "styles": {},
  "onMount": [],
  "graphics": {},
  "commands": {
    "Countdown": {
      "parameters": [
        {
          "name": "seconds",
          "default": 99,
          "type": "number"
        }
      ],
      "commands": [
        {
          "type": "SetValue",
          "property": "text",
          "value": "${seconds}"
        },
        {
          "when": "${seconds > 0}",
          "type": "Sequential",
          "commands": [
            {
              "type": "Idle",
              "delay": 1000
            },
            {
              "type": "Countdown",
              "seconds": "${seconds - 1}"
            }
          ]
        }
      ]
    }
  },
  "layouts": {},
  "mainTemplate": {
    "parameters": [
      "payload"
    ],
    "items": [
      {
        "type": "Container",
        "width": "100vw",
        "height": "100vh",
        "items": [
          {
            "type": "Text",
            "text": "",
            "onMount": [
              {
                "type": "Countdown"
              }
            ]
          }
        ]
      }
    ]
  }
}

countdown-elapsedTime.json

{
  "type": "APL",
  "version": "1.3",
  "settings": {},
  "theme": "dark",
  "import": [],
  "resources": [],
  "styles": {},
  "onMount": [],
  "graphics": {},
  "commands": {},
  "layouts": {},
  "mainTemplate": {
    "parameters": [
      "payload"
    ],
    "items": [
      {
        "type": "Container",
        "width": "100vw",
        "height": "100vh",
        "items": [
          {
            "type": "Text",
            "text": "${Math.max(99 - Math.floor(elapsedTime / 1000), 0)}"
          }
        ]
      }
    ]
  }
}