moodchecker
nounUK /ˈmuːdˌtʃekə/
US /ˈmuːdˌtʃekər/
A moodchecker is a thing or person that finds out how you are feeling.
My teacher used a moodchecker to see who was happy and who was sad today.
OTHER MEANINGS
2. A small app or tool that asks you to pick how you feel each day.
I tap the moodchecker on my tablet every morning before school.
3. A person who quietly watches how a group is feeling.
As the team's moodchecker, she noticed everyone was tired after lunch.
4. A quick look at someone's face to guess their mood.
One moodchecker at the door told him his brother was grumpy.