Alex this would be nice but only if we could use it with iTunes file sharing features! And for seven dollars? I don't even know if it is accessible!
I would like to share a tip for an advanced and accessible FTP client for iOS, FTP Client Pro for 3.99 USD.
It supports FTP, SFTP and FTPS (FTP over SSL/TLS), can edit text files like TXT, PHP, CSS HTML, etc. in the built-in text editor, compress to ZIP archives, unpack ZIP and RAR files, change file permissions and has some other advanced features. For more details, check the [app directory entry for FTP Client Pro, but don't confuse this app with another app in the App Store with the same name, which is free of charge but missing some features and is not very accessible..