If you want to add autostart apps to your Fedora remix there is one quick and easy way to do it.
Open your kickstart file and find section that starts with “%post”. Any command that you issue in %post section run with root privileges in build environment before iso image is created.
Any application that you add to ~/.config/autostart folder start up in GNOME 3 when user logs on. To make this system wide you need to put your application shortcuts in /etc/skel/.config/autostart directory
so here is one example how your kickstart could look like:
# add synapse to autostart directory
mkdir -p /etc/skel/.config/autostart
cp /usr/share/applications/synapse.desktop /etc/skel/.config/autostart/
Now you can add any app that you want to start every time users log on.