Right now, the only way to close an application so that people who have already started one cannot continue it (if admissions acceptance of applications has closed) is to decline those people, and that has to be done one-by-one.
It is strongly recommended that you create the ability to set an end date for an application to accept responses, just like that which exists in forms. It would be even better if, as part of this, there was an ability to choose whether to automatically decline all people currently in progress with that application on that end date. Or, to be able to change application statuses in bulk from the Applications page.
