The Guardian's iPhone app has been downloaded more than 400,000 times since its launch in January, while the newspaper's separate mobile website now accounts for more than 10% of total digital traffic.
Guardian News & Media, publisher of the Guardian, the Observer and the guardian.co.uk website network – which includes MediaGuardian.co.uk – revealed the first usage figures for the iPhone app on Friday.
The Guardian app, which debuted in the Apple's App Store on 19 January, has been downloaded 403,388 times to date.
The app offers limited access to some Guardian content for free, while users can pay £2.99 for six months, or £3.99 for an annual subscription giving full access. The figures show that 67,258 users have opted for a paid-for subscription.
In the US, where the app is free and advertising funded, there have been 36,089 downloads.
Guardian.co.uk's mobile website, m.guardian.co.uk, was relaunched in November. The new site has seen a surge in growth, with 10% of total traffic to the Guardian's web presence now coming via the mobile platform.
In April the Guardian's internet site, guardian.co.uk, attracted 42,785,039 monthly unique browsers. The mobile site drew 4,287,503 monthly unique visits in the same month.
This time last year the mobile site accounted for just 4.5% of traffic; in 2009 it was just 0.6%.
"We've seen an incredible growth for the Guardian brand on mobile in the last two years," said Janine Gibson, editor of guardian.co.uk. "News on mobile is no longer only valuable to people who read the news, but also to people who are a part of it. The 2011 news agenda in particular, such as rolling events in the Middle East, has proven how there is a massive appetite and need for access to insightful, reliable news on mobile devices, and we're proud to be a major player in this."
The Guardian's old iPhone app, which was launched in December 2009 and has attracted more than 200,000 downloads, carried a one-off charge of £2.39. It stopped being sold when the new app went on sale, but continues to work.