Download page for the unrestricted 30 day trial version 
which can be used to update your licensed older version.
Click  the 'Open download page' button at the bottom to proceed. Answering the questions below is not mandatory.

Installing the fully functional 30 days trial version onto your Exchange Server is a zero risk operation. It will not add or replace system components and will not impact the service pack level or post-fix updates  performed in the past. The setup will only create a new folder and place two files on the server but Exchange Server does the work...as it was designed to do!
Exchange GroupCalendar works without an external (sql) database or other external technology.  It's a purely Exchange server based tool using its full potential without installing potentially damaging dll's or replacing any sytem components.