TouchTop is installed using a simple web installer: since the software is hosted in a central repository you will always get the most updated version at the time of first installation.
The auto-update will also check for updates on every execution.

 

Starting the Installer

 

Just execute the installer you received.
Be sure to have obtained also the license file, that will allow you to complete the installation and activate your edition of the software. 
The license file is distributed as a simple file with the ".tabulalicense" extension, it can be either time-locked (for evaluation purposes) or hardware-locked for permanent installations.