You can’t rely on neighbours. Our alarm at home has gone off twice while we were looking after someones’s cat and neither time did anyone tell us the alarm went off.
I’ve just bought the Ring video doorbell and have two old phones upstairs in a window with the app Manything and that is working ok but I will be buying another 1-2 ring cctv cameras. Really impressed and think cloud is the way to go with cameras. Was going to get Nest but the cloud storage pricing is way too expensive.