The Guardian newspaper has launched an iPhone application which offers a range of features to help readers stay in touch with content.

Formatted for iPhone and iPod touch, The Guardian costs £2.39 and becomes one of the first news applications that users must pay for.

Developed internally along with mobile agency 2Ergo, The Guardian hasn't ruled out the possibility of charging for extra functionality at some point in the future.

The newspaper also hopes to add video content in the near future.

The iPhone application offers topic-based search, the ability to download and read content without internet connection using the 'offline reading' option and the opportunity to personalise your home screen.

According to The Guardian, the application will check for the latest content every time it is opened or after every 15 minutes of use.

Available from the Apple iTunes App Store, The Guardian costs £2.39 and requires the iPhone 3.0 Software Update.

Around half the visitors to The Guardian's dedicated mobile site - - do so via Apple's handsets.

Earlier this month, The Telegraph newspaper launched a new and improved version of its news application, which is offered free.

The update offers readers a chance to share stories or pictures via email, Twitter or Facebook access video reports and picture galleries.