The App on my iPad is crashing / closing

There are a couple of things that you could check on the device: 

Check that you have updated to the latest version of the app

- Go to the PlayStore to see if the app needs updating, it is important that you update it rather than uninstalling and re-installing the app.

Check that you are connected to the internet

- It is worth double checking that you are connected to the internet. You can do checking that you can successfully access a web page.

Check the Firewall Settings

Can you ask the team that manage the firewall/proxy to disable/clear caching and allow traffic for ports 80 and 443 for the following domains.

*.theteachercloud.net

*.evidenceforlearning.net

*.s3.amazonaws.com