I understand you're looking for the free download. However, I must clarify that ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) does not offer this software for free legally. Version 7 is a paid tool typically included with certain ASHRAE handbooks or available for purchase to members and non-members.
and Google Play for HVAC service technicians that includes psychrometric calculations. Duct Fitting Database Lite: A free version of the duct fitting tool for iOS. ASHRAE Psychrometric Chart App: Ashrae Psychrometric Analysis Cd Version 7 Free Download