From the trial page:
Save more. Get the most out of your data plan by harnessing the Nokia Xpress internet platform behind the app. It automatically compresses data by up to 85% so you use less of your data plan and save battery charge, all while rapidly getting to the sites you care about.
Discover more. Use the convenient Nokia Xpress for Lumia start screen as a jumping off point to the latest that the web has to offer. Convenient, time-saving features enable you to rapidly retrieve your favorite content and quickly share with your social network.
Do more. Nokia Xpress for Lumia also includes several new and interesting features to deliver a uniquely Nokia experience on Windows Phone.
Here's the launch video:
Nokia Xpress for Lumia offers several tools for controlling your data usage. Data usage and savings are reported as a live tile on the start page and via a detailed dashboard in the app, giving you a quick view of your data usage and savings. Additionally, you can store any web page locally to view later from the “Saved Pages” screen, even with no cellular data connection.
The Nokia Xpress for Lumia start screen can be used as a jumping off point to the latest content from your favourite web sites. A 'Magazine' feature automatically asks you if you want to add sites with RSS feeds to your collection as you visit them. It then presents the feeds to you in an easy-to-use magazine-style layout. Another feature, 'QuickLinks', automatically adds tiles for your frequently visited sites on the QuickLinks screen and orders them based on how often you visit them.
Additional extras include tapping on a word that you want to learn more about and Nokia Xpress will discover related content with automatic contextual search for you. You can then swipe through screens of related content from Wikipedia, Bing and YouTube. One click language translation is available for virtually any web page, making more content accessible to you. Just navigate to the page you’re interested in, tap on the ‘translate to’ option in the menu and select from one of the 10 currently available languages.
We've been trying Nokia Xpress for Lumia and overall it has been a positive experience. In our tests we actually saved up to 88% on our cellular data usage. When viewing a complicated desktop webpage via mobile data, there is no discernible delay in a page being displayed. This is impressive considering that Nokia is downloading the entire web page for you and compressing all the images and page structure down into something for your phone to present.
The system provides wide tiles for each added site. When navigating within a site, all stories are showing in a horizontally scrolling vista of stories with a headline image and first paragraph, and a button to go and view the full text in the Xpress browser.
An additional feature of Nokia Xpress is that large binary files such as videos and PDF files can be downloaded directly to your SkyDrive account. Nokia Beta Labs emphasised this for downloading videos, which might mislead some into thinking that YouTube videos can be downloaded. The 'download to SkyDrive' feature does not apply to embedded content, only files directly linked to in a page. Once a file is transferred, a dedicated "Nokia Xpress" folder is created in the root of your SkyDrive.
One drawback in using Nokia Xpress is that Windows Phone does not allow you to change the default browser. Therefore tapping links in Emails (etc.) will still launch Internet Explorer. So, full time use of Nokia Xpress for web browsing will require users to copy and paste URLs, unfortunately.
It's this proxy based technology that is at the core of Nokia Xpress and is something already in use for the Nokia Browser for S40 devices. This is a key advantage that Nokia will be able to leverage in getting its devices sold in less affluent parts of the world where many people do not own a PC, and as such the smartphone fulfills that gap and peoples' only connectivity is relatively constrained mobile data connections (e.g. GPRS).
We saw today in Kantar's market share figures that low-end devices like the Lumia 610 are 'driving sales' in the French and Italian markets, and the advantages offered by Nokia Xpress could continue to drive this trend in similar markets and is in tune with Nokia's drive to connect "the next billion".