Code-Free Startup - Learn how to build real apps without coding
Bootstrap 4 Cheat Sheet - An interactive Bootstrap 4 cheat sheet
Code4Startup - Learn Ruby on Rails, Python, AngularJS, NodeJS, React, Ionic by cloning AirBnb , TaskRabbit, Tinder, Product Hunt, Fiverr and . more.
HackerThemes - Bootstrap 4 themes and tools for web developers
Codeplace - Learn how to code by building real web apps
Bootstrap Zero - Open-source, free Bootstrap templates collection.