An updated version of Skype for the iPhone and iPod Touch is now available for download.
Skype, the voice over internet protocol (VoIP) software company, is now the world's biggest carrier of international telephone calls.
According to market analyst Telegeography, Skype's international voice traffic grew 41% to 33bn minutes, 8% of the world's total last year.
The updated version allows users of the iPhone and iPod Touch with OS 2.2 or later to access Skype voicemail and send text messages.
According to Skype, there have been more than 4 million downloads of Skype for iPhone since the application was launched 31 March.
Users can download the Skype 1.1 update in iTunes or launch the App Store on their device and select Updates to get the latest version.
Skype has also updated the language support for the iPhone app, and it is now available in 17 different languages.