I have an auto doorbell setup:
Detects if someone is walking towards the door (will not trigger if walking away from door) and it then takes an animated GIF and uses pushover to send the movie of the person walking to the door. It also plays a doorbell sound on chromecasts around the house. Works well and used because family will walk in our back door unannounced and wont ring any bells and our dog knows them. I get video of all visitors in realtime saving time each night reviewing footage.
I have a roll your own babymonitor that when crying is detected it can do any combo of these depending on switches that can be turned on and off as required:
I can push messages when the baby is crying to multiple phones.
Blink a certain light to the colour red then back to previous setting.
Display a text message on my TV
Cast the video to the TV or home hubs screen with audio.