Cant get Toolbar to show up in Node Webkit

I have what should hopefully be a simple question. According to the documentation, and tutorials that Im looking at, a basic nw.js app should have a toolbar at the top as such. However, when I run my 'Hello World' program I have no such toolbar, it looks like this:

I also tried to explicitly turn on the toolbar in the package.json (although it sounds like it should be enabled by default), like this:

{
  "main": "index.html",
  "name": "example",
  "window": {
    "toolbar": true,
    "width": 800
  }
}

But I still get no toolbar. What am I missing?

my version of nw.js is 0.13.0 (windows 64bit)