This my remix of the “useless box” based on the kit published by justaddfilament.com.

You need the parts as listed in the parts list. Justaddfilament sells them as a kit.

Because i had problems with the thread inserts I reduced the 7 holes for the inserts to 2.5 mm and threaded them after printing. One hole is a bit difficult to thread because of space. Here you could also use a small self threading screw.

The provided step file had no screw hole for the 3mm bolt to secure the arm. The here provided stl for the arm does have the hole prepared to be threaded. 

The modifiedd cad file, in Fusion360 (f3d) format, is also uploaded. This file also has a provision to add text to two sides.

For assembly instructions, and to buy the additional material have a look at justaddfilament.com. They also have other interesting projects.

I printed the design with PLA, no supports needed (when oriented correctly on the build plate).