RHEL7 - allow user to control own app using systemd

We have an application that runs as a particular user and we've recently discovered that if the application is started via systemctl as root, the app runs as that user, but for some reason the user is unable to execute the systemctl start|stop commands as itself. Is there a way, aside from a sudo entry, to allow the owner of that app to start the app using systemctl commands? I've heard something about polkit, but I don't know a lot about it so I'm not sure if it's the best method.
Thanks,