Exports 'flextable' objects to 'xlsx' files, 
    utilizing functionalities provided by 'flextable' and 'openxlsx2'.

Application of the filtered monotonic polynomial (FMP) item response
    model to flexibly fit item response models. The package includes tools that
    allow the item response model to be build on any monotonic transformation of
    the latent trait metric, as described by Feuerstahler (2019) <doi:10.1007/s11336-018-9642-9>.

A general framework for finite mixtures of regression
  models using the EM algorithm is implemented. The E-step and all
  data handling are provided, while the M-step can be supplied by the
  user to easily define new models. Existing drivers implement
  mixtures of standard linear models, generalized linear models and
  model-based clustering.

The fitting of mixtures of generalized nonlinear models is implemented as an extension of the existing package 'flexmix'.

A general estimation framework for multi-state Markov processes with flexible specification of the transition intensities.
    The log-transition intensities can be specified through Generalised Additive Models which allow for virtually any type of covariate
    effect. Elementary specifications such as time-homogeneous processes and simple parametric forms are also supported. There are 
    no limitations on the type of process one can assume, with both forward and backward transitions allowed and virtually any number
    of states.

Provides flexible odds ratio curves that enable modeling non-linear relationships between continuous predictors and binary outcomes. This package facilitates a deeper understanding of the impact of each continuous predictor on the outcome by presenting results in terms of odds ratio (OR) curves based on splines. These curves allow for comparison against a specified reference value, aiding in the interpretation of the predictor's effect.

Model selection tools and 'selfStart' functions to fit parametric curves in 'nls', 'nlsList' and 'nlme' frameworks.