Bootstrap 4 Cheat Sheet - An interactive Bootstrap 4 cheat sheet
FlowBite - Build UI interfaces and simplify the process of integrating into live websites with Tailwind CSS
Bootstrap Zero - Open-source, free Bootstrap templates collection.
DaisyUI - Free UI components plugin for Tailwind CSS
HackerThemes - Bootstrap 4 themes and tools for web developers
Tailwind CSS - A utility-first CSS framework for rapidly building custom user interfaces.