Try this in your family
Give the same five-minute warning each time.
Name the next activity before the screen goes away.
Acknowledge disappointment without reopening the decision.
Notice cooperation afterwards, even when the transition was not perfect.
Consistency matters more than perfection. A routine becomes easier when the words and sequence stay familiar.
Where Shellimit can help
Set the time and available apps before the handover, then let the visible limit support the boundary you have already explained.