VS Code is a free code editor for Windows, Mac, and Linux that lets you debug code, execute Git commands and write SASS code. It combines powerful developer tools like IntelliSense.
XD offers an intuitive UI for designing any application, from smartwatch applications to full-fledged websites, and it provides handy tools for creating wireframes and prototypes.
A popular prototyping tool for web developers and designers, Figma gives you vector tools for fully-fledged illustration, prototyping capabilities, and code generation functionality.
GitHub allows you to organize projects into repositories on a single platform. Maintaining branching strategies is pretty easy, and it's a great tool for building projects in a team.
Bootstrap is a powerful library for creating and customizing mobile-friendly responsive sites, and also features SASS variables and mixins, and powerful JavaScript plugins.