Marking its foray into Garmin and Tom Tom-dominated turn-by-turn GPS navigation market, Google is coming up with a ‘free’ turn-by-turn based navigation application that will also support voice-guided directions.

The free app, likely to deliver a blow to several location based navigation service providers whose services come at a premium charge, will first become available on the Android-based phones.

Going by the demo video of the Google nav app it is evident that the app is a fully well-developed one, and is capable of becoming a useful tool for dexterously blending Google's map and street views with traffic information and voice commands.

The Google Maps Navigation app, which would have an ad-supported model within the free app itself, would likely have a notable effect not only on the GPS kingpins, but also on the overall smartphone market.

The GPS app vendors would have to resort measures like introducing price-cuts, or providing ad-supported free versions, or adding some astounding features to their high-cost services – for which they charge up to $100; to counter the hit that the new Google app may deliver.

Meanwhile, the turn-by-turn navigation feature on the Android will definitely help tempt the smartphone users away from the popular iPhone; as the app will essentially be Google’s open-source operating system platform’s first ‘killer’ app!