There isn’t a simpler way to make your dumb smoke detector smart. The Roost 9V Battery ($34.99) has Wifi built-in to the battery. This means it can alert you when the battery is low (about every 5 years), alert you when your smoke detector is alarming (even when you are away), and can be snoozed via your smartphone if it is a false alarm.
Heck, if you have ever hunted all over the house trying to find the one smoke detector with the low battery chirp you know that this gadget is worth the money. Video of the Roost Smart Wifi 9V Battery after the break.