Here is a guide to install Filezilla FTP client on Ubuntu 13.04, you can install Filezila using the Ubuntu Software Center.
FileZilla Client is a free, open source FTP client. It supports FTP, SFTP, and FTPS (FTP over SSL/TLS). It’s a full-featured FTP client with an easy-to-use GUI. It is written in C++ and uses the wxWidgets library. FileZilla supports FTP, FTP over SSL/TLS (FTPS), SSH File Transfer Protocol (SFTP) and has IPv6 support. Visit the Filezilla Homepage.
To install Filezilla click on the link below
When the software center is opened click on the Install button and enter your password to authenticate the installation. When Filezilla is installed you can close the software center, to start Filezilla press the SuperKey and type: filezilla
How to open the apt link? Read this article.