This Wear OS app is designed to assist Hard of Hearing (HoH) skaters to tell when roller derby jams start and stop.
For example when a jam is called, the device will buzz-buzz-buzz-buzz x3; rolling whistles are "haptic'd" via a single 1s long buzz. Lead is indicated via 2 buzzes, while intermission start / end is indicated with a single 10 second buzz.
Note that to facilitate the use of the watch's vibration device, this app must stay active and also disables the screensaver while running.