I had a major issue with two parents not being able to sign in ther accounts, and I thought they were typing in their info wrong. Turns out they had iPhones, go figure! THANKS a lot for posting, reading that helped me understand my problem.
The current work-around is to just open Safari or web browser on the iPhone and log in via Unified Classroom. So they have access on their mobile device.
Thank you for posting an update in the thread to allow other users to update the app in an attempt to login to the PowerSchool Mobile app to see their child's 2019-2020 school year information! @karschamroon
Please note, the PowerSchool Mobile app credentials will be different than the Unified Classroom parent portal account credentials. I recommend reaching out to your child's school to request assistance accessing your credentials to access the PowerSchool Mobile app.