It's pretty easy. I added a bunch of smart technology over the last 2 months. I don't have a smart lock but have considered buying
The August Smart Lock, the style just doesn't fit my house (mid century ranch) so I haven't bought one.
Here's my setup:
- Android Phone (Google Pixel XL) with the Google Home app
- Google Home speaker unit
- Philips Hue Started Pack Generation 3 + extra bulbs
- Philips Hue remote light switch/dimmer
- Nest Thermostat (newest)
- Nest Protect Smoke & Co2 Detector (newest)
- Honeywell Alarm system
- Roomba 650
Setting up the system is really pretty effortless. I started with Google Home, the app for Android that Google provides, which allows you to quickly add devices to your house. You do this by downloading the apps for the devices that you buy. Philips Hue has an Android app and you register for an account through Philips and then in the Google Home app, you ask that Google home can control your Philips Hue system. Likewise with Nest. You download the NEst app or register for the NEst website and then use Google Home to request control of the Nest App. You could use all of the apps separately, but it doesn't make sense and it's better to just use one to do everything for you.
My Honeywell alarm is connected to Google home but it's not well supported by Honeywell. I can set and release the alarm and check a very basic history, but the Honeywell website login thing is much more detailed, so I'd use that if I wanted to.
Beyond that, because I have a GOogle Home speaker, I can tell the speaker to do things and it pretty much just works.
"Hey Google, turn off the lights" -- turns off my living room lights.
"Hey Google, set the lights to light blue, at 60%" -- does exactly that...
"Hey Google, what temperature is it in the house?" -- "It's 62 degrees," -- "Ok, turn it up to 70 degrees." -- "Okay, setting temperature to 70 degrees."
"Hey Google, test the smoke alarm." -- "Ok, testing..." (beeeeeeeep)
"Hey google, turn on the stay alarm" -- "Ok, setting stay alarm to ON" ('Alarm Set')
"Hey Google, ask roomba to start cleaning" -- "Ok, starting the Roomba"
It all works, basically, flawlessly. There's some added features Google home needs to add... Like the stuff we use the most with Philips Hue is the ability to make "Scenes" with multiple lights, where it spreads a color gradient evenly across the whole room using multiple light sources, and Google home does not allow you to set scenes yet, so I have to use the Philips Hue app for that...... but it's like 3 taps.
As you add more devices, you just add more stuff to Home, and it works really well, and it all communicates with each other. Using free services like If This Then That (IFTTT.com), you can easily add "recipes," so let's say you get home on a friday and say, "Hey Google, it's beer time," then you can have that phrase trigger relaxed lighting, set the air conditioning to 62, have your Chromecast play the football game, and then have the speaker start playing a preset playlist. Now, that's kinda exhibitionist and silly, but some of them are great... like a recipe that, at 6:45am, sets the heat to 68, slowly starts turning up the brightness of your lights, and then starts to quietly play your morning radio brief from NPR... Or, as soon as your phone is, say, 15miles away from your house on your commute home, it triggers the AC to turn on and the outside lights so that the house is comfortable and well lit when you get home.
Other systems like smart coffee makers, washer or dryer, etc, can be added and that's probably my next big investment in this stuff. I really get a kick out of it and I like it a lot. It's all completely unnecessary but it's one of those stupid things I enjoy.
-- edit --
ALso you aren't tied to just one ecosystem, though I like that Google's is cross-platform. Apple HomeKit is similar to Google Home (App/service), but of course, it's iOS only. I currently have Google Home on my iPad and even though I don't have Hue / Roomba / Nest / etc on my iPad, I can still do all of the commands from that and it works with the services I've synced to it. Amazon Alexa will also work with all of these devices as well, and I think Alexa even supports setting 'Scenes' in Philips Hue, something that Google Home doesn't support yet.