Conor Dougherty wrote a most insightful article in the Business and Innovation section of the Irish Times on Monday, 11 January 2016 called "Growing up mobile: app dings and pings become soundtrack of millennial youth". It explains how app development companies are responding to teenagers needs to have constant alerts and how teenagers manage the apps that they use on a daily basis.
In a further article in the same paper, Karlin Lillington on Thursday, 14 January, gives a further slant to the implications of this behaviour in "Teenagers risk being defined for life by their social media posts".