If you need to temporarily remove a parents access to the app, you can do this by changing the parents contact priority order from 1 to 3 or above and changing the parents app permission to No.
Open the student profile, under Contact Information expand the parent you want to change and click the cog to the left of their name.
Change the Contact Order from 1 and update 'Allow Contact by App' to No then press Save -
*Remember to do the same for any siblings.
This removes the child from the parents app and a message appears to the parent saying:
"Your account does not have access to any children. This could be because of changes made by the school, or your child leaving the school., If you have any questions please contact the school office."