Multifitting is a computer program that was originally designed to model the reflection and transmission of shortwave radiation by multilayer nanofilms. Three years have passed since the introduction of this software, and in this paper the focus is on describing the possibilities of Multifitting with regard to off-specular diffuse scattering and grazing-incidence small-angle scattering. The approach to the user interface and to working with the structure model remains the same, and the emphasis is on the ergonomics, calculation speed and intensive use of the program for technological and research tasks. However, the scope of the program has been expanded to make it more useful to existing users, and it may also be of interest to a wider audience.