Smartphone Free Childhood:
https://www.smartphonefreechildhood.org/
A video for 10-12 year olds whose parents are reluctant to go down the smartphone route:
A tool for teens to understand the large-scale impact of screen time:
https://www.smartphonefreechildhood.org/resource/time-muncher
The same tool in a TED talk:
https://www.smartphonefreechildhood.org/resource/battle-for-your-time-dino-ambrosi