Hi Junie,
They are really simple to work, in fact, once you've set it up the person with dementia doesn't have to do a thing! You can go to an app on your phone and click drop in and then you pop up on the screen, can see/hear whatever the camera is pointed at and they can see/hear you.
They come in different sized screens, we have 2x 5-inch screen (£60 apiece) that I put in areas of the house they're not in as often but that occasionally my Dad was getting agitated in (hallway on the way to the shower, etc) so that I can pop up and calm him down when he's agitated. But we have a10 inch screen as well in the kitchen (more expensive, I think £170 but you can get refurbished ones off amazon for cheaper) - I have to say this is a lot better, as they don't always look at the screen with the small ones (however still a godsend as it means I don't have to wait for the stress over them answering the phone and its everyone can hear everyone). There is a middle priced/sized one at 8 inches as well.
They also work like any other Alexa device, so you can play music by asking it 'Alexa play X', and as the person who has it linked to an app on your phone (or Amazon fire tablet - about 60 quid) then you can also choose to play them music by operating it yourself remotely.
I sound like a salesman, but its been great during COVID, we can see each other, there's zero stress about it and it works off the WIFI.
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