Master the Art of Crafting Responsive Web Apps. A must-have DevTool for all web developers that will make your job easier. It's free and open source too!

Single-spa is a javascript framework for front-end microservices. Use multiple frameworks in a single-page application, allowing you to split code by functionality and have Angular, React, Vue.js, etc. apps all living in harmony.

Add a dark-mode / night-mode to your website in a few seconds. This library uses the css mix-blend-mode in order to bring Dark-mode to any of your websites. Just copy paste the snippet and you will get a widget to turn on and off the dark-mode.