after moving to a new house the wife was worried that if some rapscallion entered the house she would not be able to hear the doors open (door are usually unlocked) if she were upstairs, so a small announcer system was created with parts i had on hand, this has grown substantially in functionality over the last year.

currently the system does the following.

all 3 doors announce, when they are opened, locked & unlocked via voice message and push notification.

house secure notification when all door locked (great for people with OCD)

doorbell sound and notification.

remote checking of door and lock status.

Children's playstation notifications (stops then playing it at 4am) 

internal/external temp/humidity & barometric pressure

heating circuit & water tank temp (know if there is enough warm water to shower)

remote control of lights in sitting room/dining room/garden/man cave

cable box remote activates lighting scenes so that you do not have to use the iphone app to change scenes