Do you ever have trouble getting your duplicates to run on time?  If so the Duplicate Bridge Movement Timer could be for you - you will be amazed how well behaved players are when a machine tells them to move!  Bridge Timer runs on any Windows 95 or later laptop or desktop computer and displays a clock that runs down second by second to let everyone in the room see how long there is left for the current round.  With 2/3 minutes to go before the end a chime sounds to warn everyone to hurry up and not start another board if they are not on their last one: