Skype has claimed that five million consumers have downloaded its iPhone 3G VoIP application since it was released at the weekend.
The 3G capabilities in the Skype 2.0 application mean that users are not restricted to the availability of a Wi-Fi network when they want to make calls.
The application was designed to allow customers to make and receive free Skype-to-Skype calls for a trial period until the end of this year, and call mobiles and landlines around the world at low rates. However, Skype has said that it will announce calling rates in the coming months.
The firm claimed that Skype 2.0 for the iPhone has near CD-quality for Skype-to-Skype calls using wideband audio on the iPhone 3GS or the second-generation iPod touch.
The application also boasts improved start-up time and an enhanced call quality indicator, which Skype said helps customers choose the best moment to make calls.
The news follows a report from analyst firm Juniper Research last week which predicted that 100 million people will be using mobile VoIP services within two years.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago