General Revised help-files for r2() and icc(), also by adding more references. New functions re_grp_var() to find group factors of random effects in mixed models. Changes to functions omega_sq() and eta_sq() give more informative messages when using non-supported objects. r2() and icc() give more informative warnings and messages. tidy_stan() supports printing simplex parameters of monotonic effects of brms models. grpmean() and mwu() get a file and encoding argument, to save the HTML output as file. Bug fixes model_frame() now correctly names the offset-columns for terms provided as offset-argument (i.e. for models where the offset was not specified inside the formula). Fixed issue with weights-argument in grpmean() when variable name was passed as character vector. Fixed issue with r2() for glmmTMB models with ar1 random effects structure.