Open Chrome hosted app in a separate toolbar-less window. Also see: https://developers.google.com/chrome/apps/docs/developers_guide

manifest.json

{
    "name": "My App",
    "description": "This my app.",
    "version": "1.0",
    "manifest_version": 2,
    "app": {
        "urls": [
            "http://example.com"
        ],
        "launch": {
            "web_url": "http://example.com",
            "container": "panel",
            "width": 1200,
            "height": 768
        }
    },
    "icons": {
        "128": "chrome-icon-128.png"
    }
}