chrome/common/extensions/docs/examples/api/document_scan/background.js

// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

chrome.app.runtime.onLaunched.addListener(function() {
  chrome.app.window.create('scan.html', {
    singleton: true,
    id: "ChromeApps-Sample-Document-Scan",
    bounds: {
     'width': 480,
     'height': 640
    }
  });
});