Needed one since I have limited desktop space and switches often between working on my laptop and other things. Existing designs don't seem to fit my old and thick (40mm) Lenovo Y510P laptop, so I made one. If your laptop is heavy (like mine), the springy base design enables the stand to clamp onto the laptop body and keep it more secure.
Design was made in OnShape. You can find the source file here if you want to adapt it to your need.
And if you are wondering what that logo embellished on the surface is, it's this: opensource.org