Using tkProgressBar on shinyapps.io

I have build a Shiny app which contains a tkProgressBar. When using the app after uploading to shinyapp.io, it crashed at the first call to tkProgressBar
I understand from an earlier topic that this function cannot be used when uploading.

I wondered if any workarounds have been or will be developed.

It would be quite useful to have this Shiny function working not only when running an app locally but also when it is deployed to shinyapp.io

Thank you.