KonstaUI is a framework to build web applications that look and feel like mobile apps. It's not perfect but it is quite good. I was happy with how quickly I could get things working and looking nice on mobile.
This is definitely something to add to the toolbox of quickly getting started. I'm currently building out a suite of utility apps and hopefully I can use more of the features of KonstaUI. It's only been a couple hours but I think this might be in the bucket with the Carbon Design System as gotos.