The latest version is 0.9.18 and is available here: echotracker-0.9.18.exe
You will need either Microsoft Outlook 2003 or 2007, and .Net 2.0 to run the echotracker.
If you have any questions regarding the use of the echotracker, we suggest you join the echotracker users mailing list: lists.echotracker.com/listinfo/users
You can find a source snapshot here: EchoTracker-100307.tar.bz2