The app is currently hosted here.
As of now, a first version of the 'master' and 'category_dict' files needs to be created manually, ensuring the column names, formats, etc. are strictly adhered to. This means new users can only be onboarded with the help of the developers, or by reverse engineering the data structure in the demo files in this repo. It is a feature on the issues list to add a tab for streamlined onboarding.
The app should be self-explanatory. If anything is unclear, please report an issue on the issues list of this repository, or contact me here.