I am putting a variation of the design up on github - https://github.com/FyberLabs/usb-motor/

It is a specific application that was requested awhile back.  I will be making a few variants including a powerbank, drone charger, and a brushless controller similar to this one.  The design is a bit larger, but it can be shrunk down to about the same size.  The original design would require 12-20V from the USB source.  Now it will be able to accept 5-20V for 1-4 cells in the design.  The design can obviously be reduced by a specified cell count and application.