Snapchat's teen fans wince as app catches on with their folks

An estimated 14% of US smartphone users, who are 35 or older, are on the messaging app

Paris Zeikos says he noticed a surprising trend on Snapchat. Parents have started creeping onto the messaging app, a social-media outlet long dominated by teens.

“It’s kind of shocking,” said Mr. Zeikos, an 18-year-old university student in Manchester, England. “Most people who use Snapchat are in my generation, so it’s bizarre to see someone older use Snapchat.”

Since its founding five years ago, Snapchat has become a digital mecca for high school and college-age students, allowing them to send photos and videos that disappear in a matter of seconds. It has amassed 150 million daily active users, said