It’s not the most detailed thing, but I just use a free account on cron-job.org to send a head request every two minutes to a few services that are reachable from the internet (either just their homepage or some ping endpoint in the API) and then used the status page functionality to have a simple second status page on a third party server.

You can do a bit more on their paid tier, but so far I didn’t need that.

On the other hand, you could try if a free tier/cheap small vps on one of the many cloud providers is sufficient for an uptime Kuma installation. Just don’t use the same cloud provider as all other of your services run in.

Or you can host your own instance quite easily. If you want just a new instance, pick one from the list above. Everyone who intends to run a public instance can enter it there and you’re sure, that this person intends that instance to be public.

CMG’s website addresses this with a section that starts “We know what you are thinking…”

“Is this legal? YES- it is totally legal for phones and devices to listen to you. That’s because consumers usually give consent when accepting terms and conditions of software updates or app downloads,” the website says.

Well, yes, but actually no. No idea how this might play out in other parts of the world than the US. But in most places, you’d usually need consent of all parties, that are involved. If my neighbor were to install an (infected) app like this, then carries his phone around and talks to me, I did not consent and it would be illegal to record me, even if he were not tricked into consenting, but did knowingly accept it. Worse yet, in the last scenario, he might be on the hook for legal consequences, too…

Besides that legal minefield, I thinks it’s a bluff. The tech is either way less accurate than they claim, or quite ressource intensive by either eating through your data plan on a mobile phone or draining your battery. My bet is on a PR stunt.