FireFTP is a free, secure, cross-platform FTP/SFTP client for Mozilla Firefox which provides easy and intuitive access to FTP/SFTP servers.

After 13 years and 25 million downloads later, Firefox has officially removed FireFTP and FireSSH support from the browser. Thus, I've ended support / development of the addons. I recommend switching to Waterfox to continue using the addons.
FireSSH logo Check out my new project, FireSSH!