There is a setting that allows the RingCentral App (Glip) to launch at system start up that is normally enabled by default when the app is downloaded. Your end users can change that setting by going to File and checking or unchecking "Launch RingCentral on system start". There is no current admin functions with in the application that would allow you to enable the function globally to all users on your account so I would recommend creating a new GPO to force the action.
Please let us know if you have any other questions or concerns.
RingCentral App (Glip) support engineer.