Blender 3D : The mirror sunglasses material.

This is a simple tutorial about how to create a mirror sunglasses material with Blender 2.8 version. First, create an object and add new material. Using the Shift + A keys you will need this into Shading tab.

GeoGebra tool.

The GeoGebra tool is dynamic mathematics software for all levels of education that brings together geometry, algebra, spreadsheets, graphing, statistics and calculus in one easy-to-use package.
GeoGebra has become the leading provider of dynamic mathematics software, supporting science, technology, engineering and mathematics (STEM) education and innovations in teaching and learning worldwide.
You can find over 1 million free activities, simulations, exercises, lessons, and games for math and science!
This online tool can also be used offline with GeoGebra applications for iOS, Android, Windows, Mac, Chromebook, and Linux.
Read more at the official website.
This is a video tutorial about GeoGebra 3D with Augmented Reality (Quick Modeling Demo) from the official YouTube:

Google hidden tools and features.

This tutorial is about Google hidden tools and features.
Many of the tools and online games are hidden in the Google search area.
Open your browser and search this: 10 value spinner.
This will show a spinner and you can test it.
You can find into the bottom of this online tool many features: Flip a coin, Color picker, Rol a die, Metronome, Meditate and Calculator.
This is a screenshot with the 10 values Spinner tool.