Samsung Galaxy S5's heart rate sensor

The Galaxy S5's heart rate sensor has mostly been handy for fitness gurus, but it's now helpful for the rest of us, too. Samsung has pushed out an update to S Health that uses the sensor to track stress levels; if your heart is racing after a bad day at work, you'll know. The app also tracks long-term trends, so it should be clear when you're overdue for a vacation. While S Health won't help you get rid of the annoying coworkers or personal dramas that cause stress, the app will at least make it clear that it's time to relax.

Samsung S Health stress tracking