A new documentary explores the impact smartphones and other mobile devices are having on teenagers and their social, emotional and psychological lives. “Screenagers: Growing Up in the Digital Age” examines the effects screen technology has on kids, and offers parents practical solutions that can work. The movie, directed by California-raised, New York-based physician Dr. Delaney Ruston, has played at several film festivals and is screening at schools, churches and community centers across the country.