There are so many tools that many software engineers use, below are some of the ones that I really like:
Drawing
- https://excalidraw.com/
- https://mermaid.js.org/
Text Editors
- https://zed.dev/
- https://nvchad.com/ (NeoVim flavour)
- https://www.jetbrains.com/
Testing
- https://www.postman.com/
I'm gonna keep adding to this list as I discover more :)