Its call Snap Map and lets users see when their friends are driving, listening to music or even playing tennis.
However, privacy and security experts warn users may be sharing too much — especially the teenagers who make up 22 percent of users, according to Snap Inc., the parent company of Snapchat.
If users opt in, Snap Map shares their location every time they open the app, even if it's not to share a new picture. The locations are so exact you can figure out exact addresses.
"The app is very addictive… every time you open it marks where you are," said attorney Michael Kasdan, a partner at Wiggin and Dana who specializes in privacy.