You can download a fully functional version that will expire in 21 days. To purchase the full version, please visit the Typemock site. After your payment is complete, you will receive an email with a license key. After you enter the key in the TypeMock configuration window (use Tools->TypeMock Isolator Configuration in Visual Studio, then choose Ivonna from the list of installed products), you will be able to continue using Ivonna without any restrictions.
If you don't have the TypeMock Isolator installed, you should purchase either Typemock Bundle ($899.00) or Typemock ASP.NET Bundle ($559.00)