Examine source code of Just another timer

{
  "manifest_version": 2,
  "name": "Memento mori",
  "version": "1.4",
  "description": "Deadlines reminder for your Firefox",
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "f9a8f044-65d9-4cbc-b930@gmail.com",
      "data_collection_permissions": {
        "telemetry": {
          "description": "Collects anonymous usage statistics to improve the extension.",
          "data_types": [
            "usage_data",
            "error_reports"
          ]
        },
        "third_party_analytics": {
          "description": "Uses a third-party analytics service to understand user engagement.",
          "data_types": [
            "page_views",
            "click_events"
          ]
        },
        "required": [
          "none"
        ]
      }
    }
  }
}