I am a Scrivener for Windows user. I wanted a way to split up the MarkDown output of a novel for importing into GitBook Editor so that I could work on individual chapters on an Android tablet via DropBox or some other file sharing tool. So I wrote a little utility using Microsoft Visual Studio and C#. I made the source code available online at GitHub.
It can be found at

Nice one! Great for Windows users.

I’ve many a similar utility but in Python for OS X and Linux, mostly use it for myself but will gladly open source it on my GitHub page if anyone wants to use it