I'm not using FTP that much anymore but I usually go for Transmit (supports S3, main reason why I use it) that has a "favorites" section you can sort by name or address. It's macOS only so outside of your requirements.
I was honestly going to suggest FileZilla which seems the cross platform FTP client...
If you have a "large number" of sites though, the favorites section in Transmit it's going to look like an oversized and long list
I'm not using FTP that much anymore but I usually go for Transmit (supports S3, main reason why I use it) that has a "favorites" section you can sort by name or address. It's macOS only so outside of your requirements.
I was honestly going to suggest FileZilla which seems the cross platform FTP client...
If you have a "large number" of sites though, the favorites section in Transmit it's going to look like an oversized and long list
Thanks for the suggestion - I'll check it out!