Check out shinyHeatmaply https://www.r-statistics.com/2017/03/shinyheatmaply-a-shiny-app-for-creating-interactive-cluster-heatmaps/

HI! I appreciate that this has been a long time since your question, but you or anyone else reading this may be interested in this. I just developed a Julia-based GUI tool to plot heatmaps based on Python's Seaborn package, just for the reason you wanted. Though it doesn't make use of R's shiny, it's a similar environment. Just 10-15 min to get it running. Very minimal/no coding is required for this. Just need to click to input .xlsx/.csv/.txt files and a heatmap would be produced. At the minute, only heatmaps are supported. In the near future, additional plotting types and functionalities will be supported. This is the link with the full information and instruction:

https://github.com/srgk26/easy_plotting.app