I have no current method of compiling for iOS, but I was wondering if there is so much different between Mac and iOS that a compile to iOS would be impossible? I’m not talking about a full-blown app, but rather just the existing command line based system which could be accessed through SSH.
My use case would be uploading to my cloud drive directly, although, mounting my plex mount point directly into the plex app would be nice. 
You can almost certainly build rclone for ios using xgo. I use xgo in the rclone circle ci builds.
I fact the Circle CI build is spitting out IOS builds already! I’ve never tried them though. Here are the latest builds for you to try
I don’t know how you’d get a environment to run them in with IOS though. You’d need something which could give you a shell.
I tried to run them but I don’t think they’re signed. To my understanding, you have to compile using Xcode to get a signed version. There’s a free 7 day signing window for individual developers, but it needs a Mac to install on.
I’m thinking about doing this on a Mac from the office. I’ll update once I’ve managed to get xcode running on it.
I dont have a Mac unfortunately…
Let me know how you get on!
If I managed to run command line commands on iOS, would this in theory allow me to build something like an rclone browser for iOS?
In theory yes… You could run rclone serve webdav - I’m sure there must be webdav clients for IOS…
PS I know nothing about IOS 
So not as easy as just that. I think it needs a full app to run.
I don’t think this is possible or at least not as a official app.