Some how I couldnt get the synergyc command te run at GUI startup.

This worked for me:

Created a script called “startsynergy.sh” in my /scripts/ folder

#!/bin/bash
#
# START SYNERGY CLIENT
#
synergyc 192.168.1.33

chmod it:
chmod +x startsynergy.sh

Edit autostart:
sudo nano /etc/xdg/lxsession/LXDE/autostart

And add it at the last line..

@bash /home/pi/scripts/startsynergy.sh

Thats is. There are many roads to Rome and I took this ride 🙂