From LedHed's Wiki
Autostart
If you want to launch a program at login to the following:
mkdir -p /home/pi/.config/autostart touch mythtv.desktop
mythtv.desktop
[Desktop Entry] Encoding=UTF-8 Name=MythTV Comment=Autostart MythTV Frontend Exec=/usr/bin/mythfrontend --logpath /tmp
Obviously you can name the .desktop file something else and change the Exec= line to run the program you want.