I can’t open the app, a message pops up saying “Untrusted Enterprise Developer”

When you first download the app you will need to trust Nova Healthcare Limited.
To do this you will need to follow these steps:
1. Go to Settings
2. Press General
3. Press Device Management (it is generally towards the bottom)
4. Once you are in Device Management you will see Nova Healthcare Limited, press it.
5. After pressing Nova Healthcare Limited you will need to press the blue text that reads Trust “Nova Healthcare Limited”
6. A message will pop up on the screen, press “Trust” to trust Nova Healthcare Limited
7. Now you can go back to your home screen, find the app and open it.