Ann: ResApp Provides Updated Paediatric Clinical Study Results, page-112

Put yourself in the position of the FDA. Having convinced themselves of the accuracy and potential of the app, I have an idea they wont want to rush into approving it for sale to mums and dads, no matter how accurate it is. I think they would want to see it in the hands of health professionals.
Health professionals are able to assess the whole history and life situation and condition of the patient, not just the cough; and then, giving due weight to the Resapp analysis, make a balanced diagnosis and prescription.