Meet the Notafire Pro: a smart smoke alarm with a discreet design that lets you prevent tragic accidents in your home. It measures only 4.3″ inches in diameter. It can detect fire-related emergencies, including smoldering fires and CO. It supports WiFi, Z-Wave, and IFTTT rules.
The smoke alarm has an app that notifies you in case of an emergency. It also has an integrated camera to take a picture. Once you have installed the device, you can easily paint over it. More info is available here.