The Shared Game Timer is a web app for tracking turn time in board games. It can use web Bluetooth to connect to remote controls, allowing players to get rid of distracting screens from the gaming table.
This project creates one such remote control. It has a single button and via code, it can send single. double, triple clicks as well as long presses. It can also read the current player color and change the color of the RGB LED housed inside the button to show who is the current player.
All of this is programmed in Circuit Playground. Inside is a Adafruit ItsyBitsy and a LiPo battery. The code can be changed to do anything you want. The board game timer functionality is just what I used it for.