Bootstrap 4 Cheat Sheet - An interactive Bootstrap 4 cheat sheet
The Internet Arcade - 900+ classic arcade games, no quarters required.
Bootstrap Zero - Open-source, free Bootstrap templates collection.
Revi Box - Receive a box every 3 months to support refugee schools
HackerThemes - Bootstrap 4 themes and tools for web developers
GameTree - Discover the friends and games you will love most.