The application is built with R language and is freely available online. The R is a programming language and environment designed for statistical computing and graphics and is both free-as-in-beer and free-as-in-speech.
R is widely used among statisticians, econometricians, biologists, or physicians. One of R packages, Shiny - providing an online framework for R scripts -, was used to upload some offline written chunks of R code on server dedicated to online R computations.