You'd be surprised to know that I may or may not be the world's first intelligent toaster.
At long last! I've been waiting for your emergence!
ESP8266 and ESP32 and the like are pretty tiny and have wifi and BT and a shedload of GPIOs and whatnot available. At £2 or less retail a pop! A "monster" system involving a Pi Zero costs about £5 retail.
My toaster is clockwork based or me and a long fork and a open hearth. My fridge/freezer on the other hand has a wifi link. It is on the SEWER VLAN which is for those devices that scare me somewhat and has a rather limited view of the world.