Filezilla is a free file transfer client application, primarily for the desktop. It supports FTP as the primary mode of file transfer. It can support SFTP(Secure FTP) and FTPS (FTP over SSL) as well.
Installation:
For ubuntu - http://ubuntuhandbook.org/index.php/2016/08/install-filezilla-client-3-20-ubuntu-16-04/
For Mac - https://filezilla-project.org/download.php?platform=osx
For Windows - https://filezilla-project.org/download.php?platform=win64
Usage:
You need to input the IP, Port, Username and Password which are valid on the FTP server in order to connect. A connection with details can be created that will be retained across FTP restarts.