I had an extra Mic Boom arm lying around and thought that it would make for a great phone holder. I use it as a way to clear up my desk when referring to my phone and recording overhead videos while doing my projects.
The phone clamp is designed such that your phone sits in a way that you can film landscape videos properly. Although if you want to make a portrait version i provide the .f3d files to edityourself.
Use rubber bands or springs for the hooks at the back and M5 screws and nuts. I also added some foam padding on the clamps for better grip to the phone. Also added is a clamping block u can screw onto the side of your table.
Instructions are available in the Printables link!