Examine source code of Memory Challenge Tab

{
  "manifest_version": 2,
  "name": "Memory Challenge Tab",
  "version": "1.0",
  "description": "Vocabulary challenge on new tab open.",
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "icons": {
    "48": "icon.png"
  },
  "permissions": [],
  "browser_specific_settings": {
    "gecko": {
      "id": "{42615f18-379c-4a62-ae12-265ffb4d90b3}"
    }
  }
}