Description: Add-on package to the airGR package that simplifies its use and is aimed at being used for teaching hydrology. The package provides 1) three functions that allow to complete very simply a hydrological modelling exercise 2) plotting functions to help students to explore observed data and to interpret the results of calibration and simulation of the GR models 3) a shiny graphical interface that allows for displaying in the impact of model parameters on hydrographs and models internal variables.