He calls it an LED matrix “Paint Toy” because one of the features he’s included lets the user create pixel art like in MS Paint. The 10×8 grid of lights is controlled by a PIC 16F877A.

A dot matrix display is an electronic display that uses a grid of small dots to create text ... Press the Glyph button, which sits under the glass back, and the micro-LED screen can display app- or ...

Matrix Pro Is an Alternative, Portable Grid Controller Designed for Visual Performance: Featuring 64 customizable RGB-lit keys.