chess
Make sure there's no pieces between your king and rook (and also that you haven't yet moved your king or rook) and then grab your king and put it over top of your rook (or move it to the square next to the rook) and it will auto-castle for you. For example if you want to castle kingside Grab the king on e1 and move it to g1/h1 and it will castle kingside.