Examine source code of Tiny Tycoon

{
  "manifest_version": 3,
  "name": "Tiny Tycoon",
  "description": "Build a tiny tycoon on a tiny planet.",
  "version": "1.0",
  "action": {
    "default_popup": "index.html",
    "default_title": "Tiny Tycoon"
  },
  "icons": {
    "16": "img/png/icon16.png",
    "32": "img/png/icon32.png",
    "48": "img/png/icon48.png",
    "128": "img/png/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "tinytycoon@example.com"
    }
  }
}