Sometimes I see a half rating on a bottle. How is that possible?

The application supports half ratings, to the extent that you find that useful. In our experience, we know that a 4 star wine and a 4.5 star wine are very similar and we would enjoy either so we can’t be bothered with half ratings. But if you really want to get that detailed, you can indicate a half star by clicking the rating bar and keeping your finger on the screen. Then move your finger slowly right or left and you will see the half star markings.