Data flow GUI for Shiny development?


Given Shiny uses reactive programming. This feels lke the perfect model to have a GUI data flow interface for building Shiny apps e.g. RapidMiner, KNIME, SAS EG, R-analytics flow type interface.

I can’t find one on the internet. It’s similar to this but for Shiny. Does anyone know of (or have) a plan to create one?