Do you have iOS8 and can't scan anymore?

If you have iOS8, when you first try scanning a product using Easy Diet Diary, you will be asked to give permission to access the camera function on your phone. Make sure you allow this. 

If you do not give permission for accessing the camera when prompted, then to use scanning, you will need to go to your iPhone settings, scroll to Easy Diet Diary, tap it, then tap Privacy and enable the camera.