Interesting thread. This remote monitoring and control stuff is increasingly widespread.
I have the built-in garage door open/close button on my car's rear rear view mirror. I think most newer cars have that now. Buttons for three doors. My car app has remote start/stop, too, although I saw in the manual that if you do not drive the car for a week, this functionality may become disabled. The car app will report a door left open. Probably other stuff as well that I have not noticed.
I have an app on my iPhone that lets me monitor, or start/stop my Kohler whole house generator from anywhere. It sends me notifications here in Japan that back home in Oregon it's faithfully doing its weekly exercise. The contractor who installed the Kohler monitors it as well.
Before traveling to Japan this time, I installed a SimpliSafe home monitoring system. That can be turned on or off from anywhere with an app, too. Any doors or windows get breached while it's on, I'll get notifications as to where in the house this has happened. If I don't respond, SimpliSafe's monitoring center's personnel will call my friend in the neighborhood. If he's not okay with it, then they call the cops. Meanwhile, cameras, indoors and out, are recording the activity.
Mostly for amusement, I can review short automatic video recordings of activity in my front and back yards, like my neighbor and her son retrieving a ball from my backyard a couple of weeks ago. Or I can choose to watch live from multiple cameras, indoors and out.
The SimpliSafe system, which you buy by components depending on your needs, cost me less than $500. While out of country I purchase their full up monitoring for ~$30/month, but can turn that off when I return to the US in June. It was relatively easy to install, and the company cheerfully supplies as much handholding as you want during the install, which I appreciated.
Here at my Japan house we've had a professionally installed and monitored security system for many years. It does not, however, provide us the capability to monitor cameras from afar. (It has a camera covering the entrance to the property which the security company monitors.) So I've installed a couple of inexpensive Amazon Blink cameras, indoors and out. I think the outdoors one cost about $100. That one has a two-year battery. The indoors one cost about $35, and is powered by a regular electrical outlet. With the app on my phone and tablet, I can turn on the cameras from anywhere to see what is going on. I can set them to record activity as well for later viewing, although if you want cloud storage you have to pay for it. (Thumb drive storage is available, too.) These Blink camera are just so when we're in the US we can keep a casual eye on the place. Any breaches of the house itself will be handled by the Japanese security service.
All of the cameras above work day or night. They all have two-way voice, too.
Pretty amazing technology, at affordable pricing, out there these days.