Have a 360 degree view of your PCB design online
3D Gerber Viewer from Mayhew Labs is a free online application that allows you to upload gerber files and generate a 3D model of your PCB. It’s definitely a handy tool to check for any silk-screen, solder mask or other errors in your PCB design, before you send the gerber files to manufacturer.
3D Gerber Viewer's view of my dual power supply board
Comparison of the actual PCB (left) and the 3D Gerber Viewer output
Upload your Gerber files and have a 360 degree view of your PCB design. Pretty neat!