Examine source code of Time Tab

{
  "name": "Time Tab",
  "description": "Minimalist new tab clock, with customizable background.",
  "version": "1.5.2resigned1",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "manifest_version": 2,
  "permissions": [
    "storage"
  ],
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f645cbfb-cedd-436c-84e5-1c0670e403b0}"
    }
  }
}