Constantly harass them, of course. How can I use media to teach my kid teamwork? Try to catch their interest with something else in real life. Maybe enforce phone rules like no games because then your kid hopefully won't get as addicted to their phone in-general, that will help. Is it OK for kids to read books outside their reading levels?
Removing their phones can give kids a needed break. How Tech Is Changing Childhood. How can I use media to teach my kid self-control?
Is it OK for kids to read books outside their reading levels? When we parents were teens, we talked for hours on the phone!
How sad if screens messed up that opportunity! If your kids are having trouble putting the phone away when you ask or are engaging in other problematic phone-related behavior, consider instituting temporary time or location limits. I would recommend this as it saved us alot of arguing with him, and it really helped us controlling his phone time.