The main practical use for this for a real chessplayer, in my opinion, is to view games either online or in a chess book. You certainly need a "back" button for that. I see why "pub" mode was used to start, but I think that most people playing in pubs and thus in the same place at the same time should use a real chess set. Spectators are not going to be gathering around your tablet kibitzing, I predict.