I am curious if something like this exists as well. It would be like one of those signs that goes over the highway telling you about traffic jams or how far until the bay bridge, but house sized.
Not the same - but I have a "Reminder Rosie" clock in my kitchen. It records reminders, as you might guess from the name. It is intended for helping people with memory problems. I use it to get my 10 year old out the door in the morning on his own (having just gone nanny-less finally). It allows me to record things like "It is 7:30, time to get dressed" "It is 8:00, time to pack your lunch". The listener can only turn off the reminders by hitting the "snooze" bar but not delete them, otherwise they repeat for 15 minutes. However, you can't update it remotely - you could record something in the morning to be played later that day, but that is the limit of the flexibility. (It is also fairly expensive, although relative to the nanny it is a bargain.)