So you and your grandson are playing a game of chess online. He's viewing it through his phone, and you're viewing it through your own.
In order to coach him, he shows you his phone and you point out the move to play.
I don't know about visual chats, but there is a way to use one phone as a board for the both of you to play on, just as if it were a real board. I think this would suit your needs, unless you mean you two are skyping from separate locations and are showing each other your phones over the video call.
Is there a beginners level chess app that allows visual chat... is there such a thing?
I am a probably beginner level chess player. maybe a high level beginner, but anyway, I am teaching the game to my grandson via phones. He holds his phone to show me the chess board and I coach him, telling him where to move my pieces as we play. Is there an app which would make such a way of playing easier to facilitate? TIA