A developer preview of a tool to adapt Chrome browser apps for Android and iOS devices was released Tuesday by Google. The move extends the reach of a new kind of browser app that can also work outside the browser.

In September, the company introduced Chrome Apps, which it said combined the advantages of the Web with those of locally installed software. The new Apps can launch from the desktop, be used offline, and run outside the browser. They can utilize built-in sandboxing for security, and can connect to the cloud, be automatically updated or sync with any desktop device.

Examples of the Chrome Apps include Pixir Touch Up for modifying photos, the Wunderlist to-do list and Cracking Sands racing game.

'Packaged Web Apps'

Such combinations of Web apps, native apps and local software have been dubbed "packaged Web apps," and Mozilla's versions are called "packaged Open Web Apps." Mozilla notes that Open Web Apps are the same as standard Web sites or Web pages, except that they can be installed on a device, work offline, and have access to device APIs for interacting with cameras, address books and other on-device capabilities.

Google has released in developer preview a toolchain software tool that enables Chrome Apps to run on Android and iOS devices, through the use of the open-source Apache Cordova mobile framework. Cordova is used to build native mobile apps with HTML, CSS and JavaScript.

The toolchain, Google said Tuesday on its Chromium Blog, "wraps your Chrome App with a native application shell," thus allowing it to be distributed through the Google Play marketplace or the Apple App Store. Chrome APIs are accessible to the Chrome Apps, including OAuth2 sign-in, message pushing, sockets for sending and receiving data over TCP and UDP, and alarms for running scheduled tasks. A library of APIs is also available in the Cordova platform.

Simplification, LEGO

Some observers are questioning whether these converted apps will suffer performance hits or be second-class citizens in their ability to access functions on Android or especially iOS devices. There is also some speculation that this move takes Google one step closer to combining its Chrome OS, which relies heavily on the Chrome browser, and its Android platform.

Al Hilwa, program director for Application Development Software research at IDC, told us that the Chrome browser "is itself an environment for running apps," not unlike similar capabilities in, say, Safari or Internet Explorer, but there are also "some APIs in Chrome to access devices."

He added that "most of what they're doing has already been done in various ways with Cordova, but they're simplifying it."

The Chrome browser is also receiving attention recently because of a new, in-browser app that the company built with LEGO. First developed in 2012 by Google Australia as an experiment, it allows users to build LEGO-based virtual constructions. The app, now open to the public, is integrated with Google+ for sharing Builds.