From version 2018 onwards, Pixel Farm products such as PFClean or PFTrack must be installed and ran using PFManager.
The versions dropdown menu can be used to install or uninstall particular versions of each product, or select which version of a product to run when multiple versions have been installed on the same machine (see here for further information regarding the versions menu).
Once a version of a product has been installed and a suitable entitlement has been activated, the product logo button will become active. Clicking this button will launch the application.
Please note that whilst PFManager should be used to manage entitlements for products prior to 2018, installation and running of these older versions of PFTrack or PFClean should be done using the standard application installers available for download in your account.