FaceTime is Apple-device only. And very few iPhone owners [that I know] use anything except FaceTime for video (unless prompted otherwise). It could turn into a convenience thing, if Grams and Gramps are asking the kiddos to use something other than their default video software, the kiddos might not call as much.
They currently use FaceTime (on their phone?), so why isn't that working? Do they need/want a larger screen? Pretty sure Apple has an HDMI dongle for that. If you don't like wires, an AppleTV unit would be the choice.
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