I would like one that was just red and green. By default: red. Then I can shift it to green which automatically starts a countdown to shift to red after 15 mi

I would like one that was just red and green. By default: red. Then I can shift it to green which automatically starts a countdown to shift to red after 15 minutes. It would be even better with the countdown being visual with a bar of lights that starts up "full" and then decreases by one light until the time has expired. Must have the feature to extend the conversation should that ever be a desire. You can find good conversations with luck. Most desired for me would be automatic detection of conversation and start the countdown.