TxyPxy is an app that lets you simulate the mixture of two components, and get information on the various aspects of the composition by manipulating the temperature, pressure and ratio of each component in the mixture.
This application uses Antoine constants to simulate a binary mixture, and lets you manipulate the temperature, pressure and ratio of each component to get the overall liquid composition and the composition of each component in vapor and in liquid. Through an interactive plot, you can view your mixture in a Temperature vs. Fraction or Pressure vs. Fraction to understand and see the results of manipulating factors.
You can choose two chemicals to mix, and provide their Antoine constants, and even save simulation information for reference. You can also use your choice of units for temperature and pressure, and also switch between mole and mass fraction.