While news organizations have been publishing content in various electronic formats for some time, they have all embraced tablet computers - mostly notably Apple's iPad - as the newest device to bundle and deliver their information.

Apple's App Store lists more than 3000 applications in the News category alone, with seemingly everyone with something newsworthy, or what they believe to be newsworthy, eager to get their information in front of readers.

This rush to attract eyeballs is not surprising, given the declining readership of many print-based publications and the ever growing number of people accessing their news from a sophisticated new assortment of mobile phones, notebooks, e-readers and now tablet computers.

With nearly 15 million iPads sold in the first year, and new tablets on the market and on the way from Motorola, HP, BlackBerry, Samsung, LG, Dell, Sony and others, it's easy to see why news publishers are keen to design software applications and format their content for the tablet medium.

For news junkies, the tablet computer is a hard-to-resist delivery mechanism - a fact clearly not lost on the publishers themselves.

Unlike smart phones, which can be difficult to read from and are limited by screen space, most tablet screens are about the size of a sheet of copy paper, giving them adequate real estate to display articles, photographs and other multimedia content on a high-resolution colour screen that can be read from for many hours without eyestrain.

Tablet devices are light and portable, which means you can comfortably read your news on the sofa, the subway or at the poolside - conditions that are sometimes problematic with a laptop computer and generally impossible with the desktop machine. While some news applications update regularly throughout the day and contain original content from a single news organization, others act as RSS news feed aggregators, allowing you to skim through article teasers and tap on headlines to read articles from a wide variety of sources.

Some applications have the look and feel of a printed newspaper or magazine, while others include more inventive methods of presenting their content.

Many include interactive features such as pop-up information boxes, localized content, videos and audio and most allow you to save or send an article to email, Facebook, Twitter and other social media. Many publishers provide both their iPad application and their news content for free.

Others charge a fee to purchase their iPad app and access to their content, while yet others give you their application for free, then charge you a weekly or monthly subscription fee to have your content "delivered" each time you access their application.

Of the many news applications available for the iPad, the five reviewed below are all free and include features that reward them with a high rating from the Test Labs here at The Informr.

AP News for the iPad (Associated Press)

Rating: 4 out of 5 taps

With more than 300 locations worldwide and an army of professional journalists and photographers, the Associated Press is one of the largest syndicated news gathering organizations in the world and their content is distributed among thousands of daily newspaper, radio, television and online outlets each day.

AP News for the iPad contains much of their best reporting and all articles and photographs come directly from AP staffers. AP News is a simply laid out and intuitive application that updates its content regularly throughout the day and allows you to personalize articles based on your location. Drawing on their global network of journalists and photographers, AP News includes a wide selection of full length professionally written articles, along with a rich collection of high quality photographs and video.

All popular news categories are represented and new ones can be added and customized for a default view. Main headlines are displayed like white sticky notes on a big post-it board that scrolls left to right. Individual articles are presented as single paper-like sheets, which you scroll up and down to read and most include one or more photos or video that can be tapped to expand to full screen. With a single tap, articles can be emailed, saved or posted to Facebook or Twitter.

The reading experience with AP News is pleasantly clutter-free, the reporting is highly professional and the application includes minimal advertising. Altogether, this makes AP News for the iPad one of the best news apps available.

NPR for iPad (National Public Radio)

Rating: 5 out of 5 taps

Building on their popular iPhone app, NPR for iPad replicates their extensive playlist and newscast audio features and brings them together with a collection of in-depth articles written by NPR staff and their affiliates. Presented in a magazine style with a focus on News, Arts & Life and Music, the main NPR for iPad articles are displayed on a matrix-like home screen that you scroll horizontally through to view article headlines, teasers and display photos.

Tapping on a headline brings up the article/review/interview, which are often several pages long, along with a left-side galley that contains buttons for you to listen to the audio broadcast, add it to your playlist or share it via email, Facebook or Twitter. The bottom of the article screen contains a horizontal and dismissible scroll galley of related stories. The Topics button pops up a screen that allows you to select sub categories from News, Arts & Life and Music.

The sub categories are extensive and diverse and include everything from books to food to health to studio sessions to technology to concerts to "The World of Opera". The very bottom of every screen contains a horizontal Listen bar that allows you to access the real treasure trove at NPR - their hourly news, extensive archives of programs and list of affiliate stations. Besides a small Toyota logo on the bottom of each screen, the application contains no other advertising.

Reuters News Pro for iPad (Thomson Reuters)

Rating: 4 out of 5 taps

Reuters News Pro is an advertising free application that contains original, professionally written content from Thomson Reuters, one of the leading syndicated news organizations. Reuters News Pro's articles and multimedia content are updated throughout the day and can be customized from the main screen for the following countries: US, Canada, UK, India and China (in Mandarin).

Changing the top level country changes the main headlines and displays current local news for most top level categories: politics, markets, business, sports, technology, and more. The main news categories are stocked with ten current articles, each displayed on a single white scrollable page and very easy to read. Up and down buttons are used to move between the articles and buttons are available to make the font bigger or smaller.

A unique feature with Reuters News Pro is their hot-linked collection of hundreds of current newsworthy photographs, which can be scrolled through in a large screen format at your desired pace. Each image contains a detailed summary caption and can be tapped on to bring up a current and full length Reuters news article related to the photograph.

Other useful features include a handy up-to-the-minute full screen currency converter (with 18 of the most popular currencies), full screen charts and market data for all major stock markets, including links to current market news and analysis, and a Stocks button, which allows you to search for and display current charts and market data for individual stocks on most major markets. Stock data can be saved by tapping the My Stocks button, giving you a handy way to keep track of a collection of stocks and related market data. With its original and professional content, unique photo navigation feature and useful market data, Reuters News Pro is a robust news portal unto itself and a highly satisfactory source of top level news.

Flipboard (Flipboard Inc.)

Rating: 4 out of 5 taps

Named Apple's iPad App of the Year and one of TIME's top 50 innovations of 2010, Flipboard is a fast, beautiful way to flip through the news, photos and updates your friends are sharing on Facebook, Twitter, Google Reader and Flickr.