I travel 4 days a week for work and love being able to see my daughters on a video chat when i am gone. It feels like a real conversation compared to a phone call. I'm sure you will remember talking to him the last time more so because you could see each-other.
My prayers go out to you and your family. I am really happy that you were able to share such a special moment with your grandfather and its all thanks to the video chat feature that a lot of people take for granted.