Keep your friendships alive.
You did not stop caring about your friends. You moved away, or they did, and weeks turned into months without either of you deciding anything.
Ciao! catches that drift. You tell it how often you want to be in touch with someone: every three weeks, every couple of months. A quiet timer counts up from the last time you actually spoke. When you speak again, it goes back to zero.
Once a week, on Sunday, it shows you who has drifted. That is the whole ritual.