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.