M5Stack Cardputer is interesting piece of hardware. It's quite hard to use when flat on the desk. This angled stand will raise it by 15°. Stick rubber feet to bottom to stop it for sliding.

The stand slots into LEGO-compatible holes on the back of the Cardputer. Can be easily installed and quickly taken off.

The model is customizable, you can change the angle and optional text on the back.

To build this OpenSCAD model you need the A2D library.