A company versed in downloadable GPS driving apps for smartphones is showing off a turn-by-turn solution running on the iPhone at this week's Mobile World Congress in Barcelona.

The app, produced by Sygic, most likely amounts to an unsanctioned proof-of-concept that may face resistance from Apple when it's submitted shortly to the App Store.

Nevertheless, the iPhone Blog reports that the software, on display at the TeleAtlas booth at MWC, has turn-by-turn GPS directions with voice prompts, points of interest, support for multiple countries, and locally-stored maps. This comes as Apple has been slow to provide its own GPS turn-by-turn solution or the necessary tools for third party developers wishing to write their own.

Last July, the iPhone maker seeded a beta version of iPhone Software 2.1 with a version of the CoreLocation framework that could recognize the cardinal direction of an iPhone through GPS as well as its velocity — both necessary ingredients for turn-by-turn directions.

Two weeks before the beta seed, two veteran GPS companies, TeleNav and TomTom, said they were developing more advanced navigation software than what's offered in the iPhone edition of Google Maps. At the time, Apple product chief Greg Woswiak confirmed the hardware inside the device is just as capable as other GPS-aware phones that provide live directions.

But when Apple finally got around to release iPhone Software 2.1 last September, GPS capabilities were nowhere to be found and were presumed to have been pulled alongside experimental push notification support that was also seeded to developers as part of 2.1 pre-releases. Since then, there has been no word from the Cupertino-based company about addressing the iPhone's lack of true turn-by-turn GPS navigational software.

An app like Sygic's might have significant hurdles to overcome before it could ever be available for customers to purchase. It's believed that the iPhone SDK prohibits GPS driving apps in its current form, making it hard to see a way that Sygic's app could be approved.