This app does one thing, but it does it well. It will calculate the pressure drops and flow rates for compressible gas flow in a pipe. This app is different from other pressure drop apps in that it does not restrict the results to a certain pressure drop, which treat it as a liquid. There are 3 calculation modes that can be used:-Calculate inlet pressure: This is useful when the user knows they need to deliver a certain amount of a gas against a certain back pressure. Such as filling a tank or vessel.-Calculate outlet pressure: This will determine the residual pressure in the gas at the end of a pipe run.-Calculate flow rate: Not much to be said here, enter the pressures and you get the flow rate. We have used this to calculate free flow of high pressure lines, for example if there is a break in line (outlet pressure is zero).App includes a full database of standard pipe sizes or you can enter your own size using the Custom selection. There are over 20 gases in the database with viscosity as a function of temperature using Lennard-Jones formulation. Results are based on a modified Newton-Raphson iterative method and have been benchmarked against CFD results.Choose between Imperial or SI units.