The version you download here is complete in every way, except the program allows only 40 minutes of usage at a time. After the time period has elapsed, VTT will shut down and must be reopened again to continue use. Feel free to use VTT for a trial period of 30 days. After this period is up, VTT costs 42 USD for a personal license. Businesses should check the registration page for terms.
Registration is available online by secure credit card transaction or by mail.
Check the VTT Registration page for more information. They're also pretty cool to listen too.