To keep the low entry barrier to code development, we offer clear and up-to-date developer documentation using automatic tools [FORD (github.com/Fortran-FOSS-Programmers/ford), for instance] to generate the documentation directly from the comments inside the code. We follow guidelines inspired by object-oriented programming practice, where each step of the computation is performed in its own module with a clearly defined entry point. Finally, all parameters used in the dynamics, as well as the default values and descriptions, are defined in a collection of easy-to-read YAML files, which a Perl driver parses to generate a proper input file for the Fortran program based on the user's defined parameters.