Useful devices for home

Smoke detector and carbon monoxide detector that speaks up in a friendly voice to give you an early warning when there's smoke or CO in your home
Split Spectrum Sensor looks for both fast burning and smoldering, and tells you where the danger is
Get phone alerts so you know something's wrong even when you're away from home[1]
CO detector looks out for carbon monoxide and tells you where it's located
With App Silence you can silence the smoke alarm with your phone in the Nest app when there's only a little smoke
No chirps to tell you the battery is low; Nest Protect tests its own batteries and gives you a Nightly Promise when you turn off the lights so you know everything is working
A Light in the Dark: Usually Nest Protect has its light turned off but when you walk underneath it Pathlight can light your way.

The August Smart Lock Pro is of the easiest smart locks to fit, but it's loaded with features making it the best smart lock you can buy right now.

It fits onto your existing deadbolt and allows you to keep using your old key when you (or your landlord) want to, while still adding the benefits of a smarter lock. On test, we found it responsive and it was strong too, we weren't able to bypass it in any way. The addition of support for Alexa, Google Assistant, and HomeKit, just reinforces why this is our pick.

It is bulky and expensive compared to most other smart home products, but for those looking to beef up their smart security it's worth investing in.