After a long search I found a nice TFTP server GUI for linux.
It is called tftpgui and written in phython by Bernard CzenkuszIt
Simple and easy as it should be:
- it has a tftproot folder where you should place the files to be sent or get the files sent to the tftp server
- easy to Start and Stop
- no installation required, just lunch the script
- License is GPL, its multiplataform, supports Windows/linux/Mac