[Question] How do I create a bootstrapper?

Bootstrappers are the .exe files that download the files.

I downloaded UnSouled and it was rather cool (and a bit convenient) to have. Does anyone know how to do this?

It basically had a console inside it that showed what it was downloading and progressed down whenever the file was downloaded.

If possible, could you also show me how you could do that thing with PinaHilix (the creation by GianDeveloper)

where you could type in the console a string and it could change the exploit file's string.