Is the beep disturbing you?
This is to indicate that the thermometer has finished measuring your temperature, and needs to be different from the other sounds coming from the thermometer. A lot of our Cyclers have a partner and/or children close to them during the night, which may find the beeping disturbing.
Here is a Pro tip from our Cyclers: Turn off the thermometer after the first beep in the morning, and turn it back on after you've left the room. The latest value is shown on the thermometer for a couple of seconds, read it and enter it into the app. This will also help with the 'don't want to turn on the lights in the morning to find my phone-problem', as you will leave the room and can turn on the lights in the other room to read the result.