For meinenigma it is some things that can be downloaded.
The software or firmware to meinenigma can be found in github: https://github.com/lpaseen/meinEnigma

A paper version of this documentation is included in the kit so you don’t need to download it from here unless a newer version has been created.
You can download it to get a better idea of what you get without buying anything first but to do so you need to be registered.

Documentation – latest version:

Assembly Guide
User Guide
Enigma Introduction
MeinEnigma schematics
MeinEnigma technical drawing/dimensions
Modders Guide
Sound files

Archive – older versions:
Assembly Guide v1.10
User Guide v1.01
Assembly Guide v1.0 (green board)
User Guide v1.00