The TomTom iPhone app has been officially launched, with the sat nav giants confirming that its turn-by-turn navigation application is now being sold on iTunes.

Sat nav on the iPhone has become big news in recent weeks, and TomTom is hoping that it can repeat its success in the standalone sat nav market by getting ahead in mobile phone apps.

The TomTom for iPhone 3G and 3GS app brings either European or UK & Ireland maps and costs around £60 - more than double the price of the £26 Co-Pilot app.

"With TomTom for iPhone, millions of iPhone users can now benefit from the same easy-to-use and intuitive interface, turn-by-turn spoken navigation and unique routing technology that our 30 million portable navigation device users rely on every day," said Corinne Vigreux, Managing Director of TomTom.

"As the world's leading provider of navigation solutions and digital maps, TomTom is the most natural fit for an advanced navigation application on the iPhone."

The app brings many of TomTom's tools, including IQ Routes and safety camera position, and, although the current app is only for the two most recent iPhones, the press release promises "compatibility with iPod touch and other iPhone models coming soon".

Both Navigon and Co-Pilot have released sat nav apps for the iPhone, but there are questions as to whether an iPhone is yet ready to replace a standalone sat nav device.