For the people asking about the app, please know that not all cameras are connected to wifi. Some use batteries or are rechargeable and they actually record and save the video. The owners can view it when they return and connect the camera to a device.
Finding these can be tricky. I’d suggest Googling ways to locate them and having a look at devices that double as alarm clocks, stuffed animals, phone charging plugs etc. It’s too bad we have to think about these things!