Question: I just set up nginx as a http/https reverse proxy and it worked well.

After that, I realized that for some domains ftp services are available. I was able to install ftp.proxy and it also works well, although it just handles one single domain.

My question is: Is there any possibility to reverse proxy ftp services based on hostnames/domains like I do with nginx for http?

Answer: 
There's a G-WAN [rewrite example here](http://gwan.com/developers#handler) (look at the second handler source code, the first handler example illustrates FLV pseudo-streaming).
You can Use a virtual host, or even an alias, see the [G-WAN FAQs](http://gwan.com/faq#listener).

For more elaborate rewrites, you can use a handler, some examples are provided in the download archive.