Samsung’s S Health app has received an update and has gained the capabilities to measure your stress. All you need to do is place your finger on the heart rate monitor on the backside of the phone and the app will take care of everything else.
The app even allows you to measure your stress level over a period of time, along with the regular instant use, provided you use the app regularly. The app can give you data about your hourly, daily, weekly or monthly stress levels.
Although how much of it is accurate and not like some other gimmicky features Samsung brags about is a whole another issue that only time will tell as users test out the new feature.
[Source]