You make two separate points. There are people who are wrapped up on their phones instead of engaging with their children. That's a separate problem that's not

You make two separate points. There are people who are wrapped up on their phones instead of engaging with their children. That's a separate problem that's not necessarily addressed here. Your other stated problem seems to be with setting a digital reminder. I don't understand how a poster is superior (or even on par) in this case. If I see the poster, then I can act on the reminder. Otherwise, it would still need to be in the back on my mind for me to act on it. A small alarm is always with me, and it tells me exactly what I need to do. If we're splitting hairs about tech-oriented, what about an egg timer? Those can be completely mechanical, but it offers the same functionality in much more noticeable method. It's like a company putting up posters reminding employees to get up once an hour to stretch, take a break from the screen, and walk out your limbs for a few minutes. If I'm head down in my work, time could fly by before I even realized that it's been two hours. If my watch vibrates at 45 past the hour every hour, then the reminder will always be present.