Millions of these would not degrade signal. A random bit of metal (like a quarter, as shown for scale) in between you an a 4G tower should have the same effect as one of these devices. They are detecting existing 4G signal, not using it for energy harvesting.
Yes. I have AirTags on my fur babbies, but if I were to need to use them I'd be hoping they came within range of a device to pick them up. Then, in FindMy app, I could see where the had been, but not where they are now to go get them. I would hope a system like this could give me a much more current location. Hopefully, I'll never need any of this.
I already have some trackers on important stuff (like keys and school bag of kids if they loose it in the bus). But for other use cases it's either too large (cats) or makes no sense to have too many because then I'd have to replace a battery every few weeks ("everything else").
make it easy on yourself and change them all on the same day like a clock reset day like the recommendation for your smoke detectors. bite the bullet and change change some early to get them on the same schedule. it's worth it for sanity
It's not app or Bluetooth based (has an included detector) and it works pretty well. Battery is supposed to last a few months. It easily fits on a cat collar and doesn't bother mine at all. I've been looking for something like this for years and someone finally made one!