Truphone have announced a truphone version for the Google Android T-Mobile G1 handset, the truphone application is a free download from the Android Market and is available in the UK and US and will also become available in Germany in March 09.
Truphone offers free VoIP calls over WiFi and they claim lower cost international calls. Truphone also offers IM with support for Google Talk, Twitter, Yahoo!, and MSN along with the ability to make voice calls via Google Talk at a lower rate.
Truphone will also be adding in the near future Skype with both IM and voice calls supported. One thing though, early tested are saying the app isn’t that impressive with particular note as to how the VoIP calls are handled.
Source — android community