Truphone for Android 3.0 allows users to make free calls to other Truphone users, along with Google Talk and Skype members, when both parties have a Wi-Fi connection.
The app also intercepts calls to mobiles and international numbers and routes them over the internet, ensuring callers only pay local rather than premium rates.
Truphone says the app has a new-look interface and currently works with HTC G1, HTC Magic and HTC Hero, also available on the T-Mobile network under the name G2. Handsets running Android 1.5 and above will be supported soon.
"We are delighted to be able now to offer the full Truphone experience to Android device owners around the world", said Geraldine Wilson, CEO of Truphone.
The app can be downloaded for free from the Android Market.
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See also: Demand for Android smartphones surges