The app is not good and doesn't seem to be a priority for PowerSchool development. We do not encourage parents to use the app as it leads to more confusion than clarity.
We have shared your feedback with our Product Team and request you share your feature requests in the ideas portal under PowerSchool SIS Mobile.
You can log your request as an Enhancement Request on PowerSchool Ideas Portal so that the product team can take a look at this. This article should walk you through how to raise an Enhancement Request.