I don't like Material Design UI in my web app. That is why I don't use ABMaterial.
Edit: Can we change ABMaterial to use BootStrap?
No, ABMaterial is build around the Materialize CSS framework (
https://materializecss.com/). It was a choice we made within our company after careful deliberation because it was faster to wrap than Bootstrap and covered all functionality we needed. And with BANano, we can wrap any framework we want (see indeed the above example for Bootstrap 4 someone made). We created internally one from practically scratch (the BANanoSkeleton UI library) because we prioritize speed (as close as possible to a Native App) above all the rest.
BANanoLibraries (can) have a WYSIWYG-like behavior (as it updates the browser live when making changes in the Abstract Designer when pressing save), but requires CSS/JavaScript knowledge to
build such a framework wrap library (not very much to
use such a library). The library maker can make custom views for every component in the original JavaScript library that can be dragged & dropped in the B4J Abstract Designer. And if it is written right, allows the Live behavior in the browser.
Both frameworks are used together within our company for all our WebApps and have drastically shorted the time to go from design to production. We decided to share both frameworks with the B4J community, but have no need/time to start working on a third one.