Biological clock - everywhere

Stop your body clock ...
Stop the stopwatch exactly at the target time!
▼ What kind of app is a biological clock anywhere?
It is an app that trains your body clock while having fun!
Please compete with your family and friends!
▼ Let's aim for perfection!
If you stop it exactly, it will be displayed as PERFECT!
Please aim for PERFECT!
▼ You can select the time
You can change the challenge time to 5 seconds, 10 seconds, and 30 seconds.
The longer you spend, the more you can't stop without having an accurate body clock.
By all means, aim for perfection at all times!