Just what I needed
The app is for converting differential pressure into CFM. Whether you have a pitot probe, a flow grid inside a duct, or a Phoenix valve just measure the differential pressure, then input the air temperature and the duct size.
Not enough ratings yet to assess Air Velocity and Flow Calc.
Air Velocity and Flow Calc appears to be a legitimate app. AppsHunter Legitimacy Score for Air Velocity and Flow Calc is 80/100.
Based on 80 of 100 points across 7 verification signals from App Store and developer data.