Firstly, update the app in either the Android or iTunes. We have recently moved to a new system and the old app does not communicate with the new system.
Secondly, ensure you are logged out of all computers and devices (Phonics Hero only allows you to login once, at any time). Then try properly shutting down your app (for iPads - double click the home button and swipe it up and away) and then re-open.
If none of these work, contact the team on firstname.lastname@example.org and they will fix this for you.