cd /usr/share/applications
sudo nano myapp.desktop
[Desktop Entry]
Name=MyScript
Comment=Description
Exec=sh -c ‘/home/USER/scripts/myscript’ && disown
Icon=/home/USER/scripts/icon.png
Terminal=false
Type=Application
StartupNotify=true
Replace USER by your username
For Icon, type the whole path to your image.
Drag and drop your newly created shortcut to Ubuntu left menu bar.