Excalidraw 

Powerful yet easy to use drawing tool. Very convenient tool to make impactful diagrams fast.

Coolors 

Simple palette generator. Spacebar to generate a random combination, lock the colors you like and then keep generating. Add, move, remove, see shades, copy/paste codes from and into the app.

CSS Gradient 

Gradients for css made easy. Use the advanced color picker to make a gradient in seconds, ready to be copied inside your css.