sudo cp RPiApplication.service /etc/systemd/system/RPiApplication.service
Once this has been copied, you can attempt to start the service using the following command:
sudo systemctl start RPiApplication.service
sudo systemctl stop RPiApplication.service
When you are happy that this starts and stops your app, you can have it start aoutomatically on reboot by using this command:
sudo systemctl enable RPiApplication.service
man systemctl