The Guardian has announced significant developments in its mobile plans today. The first is a new mobile site for Guardian.co.uk, with more content from the website, topic pages, bookmarking options and faster updates as some of the key new features.

Our aim is to improve the service for those of you with smartphones, who make up the majority of our growing mobile audience. At the same time we are committed to maintaining an accessible service, optimised for smaller screen sizes and slower connection speeds, for anyone using other handsets.

According to a release from the Guardian, its mobile site in September generated an average of 507,000 page impressions a day – almost double the figure for September 2009 of 217,000. More than five per cent of Guardian News and Media’s total digital page impressions now come from mobile devices.

But perhaps more significantly the publisher has announced plans for an updated version of its iPhone application. The app initially cost £2.39 –  a one-off charge since its launch in December. Critics at the time questioned the economics of introducing an app without a subscription or renewal model. The new app, which is currently awaiting approval by Apple, will charge £2.99 for six months or £3.99 for an annual subscription.

The UK app has been downloaded more than 205,000 times since its launch. A free version of the app will be launched for US customers and the Guardian says it is experimenting with different models for different markets.