That's correct. It's called Transmit. A link for anyone who cares at this point:
https://itunes.apple.com/us/app/transmit-ios/id917432930?mt=8&ign-mpt=uo=4
Here's an example of how I used Transmit very recently. I had some very large home videos i shot on my iPhone that I wanted to show someone while I was on vacation. They didn't have an iPad or iPhone, and they wanted to view them on their TV. Luckily, their TV has the Plex app built into it, so I was able to upload from my iPhone to my home server and just give them temporary Plex credentials. It took less than an hour for me to upload them and have everything ready for this person who is not very tech savvy.
I've also been in positions where I've had to download stuff from my home server, or my online server that I needed offline, and Transmit always worked. Maybe there are other apps like it on the store, but it worked great, and it was made by Panic so it was designed to work with iOS first and only, so the quality was impeccable. I use it so much more than Coda, which I never really got into because I don't like their text editor. I'd rather write something in another app and then upload it to a server via Transmit than just use Coda.
Transmit, you will be missed :(
Edit: I just noticed Transmit is only 10 bucks while Coda is 25. I can't remember if it was always 10 or this is kind of a goodbye price. For the use I got out of it over the years, 10 bucks was a steal. I would have easily paid double, and considering it being a relatively niche product, I wonder if others would have as well.