With the help of tech start-up Yondr, San Lorenzo High School in California has banned cellphone use during the school day.

Since the last school year, students have been required to keep their phones in Yondr's locking pouches from 8 a.m. until school lets out at 3:10 p.m.

Yondr CEO Graham Dugoni was inspired to create the pouches after noticing that people at some concerts he was attending were more absorbed with their phones than with the music. Performers have flocked to the concept, with comedians such as Dave Chappelle, Jack White and Chris Rock using Yondr at their shows.

More educators are taking note, and Yondr says it has partnerships with thousands of schools in the United States, Canada and Europe. The pouches cost $15 to $30 per student annually depending on school size, and about $2 per head for large performances.

Hear from teachers and students about their experience with a phone-free school day.