The idea of the app is to combine a calculator and currency converter by introducing a linear equation to get quick and accurate results. It works as well with units of length, area, volume, mass and time; and it can also be used as a normal calculator.
For example, you could calculate lengths in feet and inches, and convert the total to centimetres. Or you could calculate bills in Dollars and Euros, and convert the total back to Dollars or to any other currency.