Interrupt someone while she’s using her smartphone and ask her how she’s feeling. If she was using an app focused on one of these areas, she’ll most likely report she was happy:
Relaxation
Exercise
Weather
Reading
Education
Health
On average, we spend 9 minutes per day on these apps.
If she was using an app focused on one of these areas, she’s most likely to report she was unhappy:
Dating
Social Networking
Gaming
Entertainment
News
Web Browsing
On average, we spend 27 minutes per day on these apps.
(h/t to Adam Alter)