Roller Derby: Jam Timer

About Roller Derby: Jam Timer Android App

The Emergency Roller Derby Jam Timer app is a virtual Jam Timer designed for Android devices to help reduce the number of Non-Skating Officials required during in-house (WFTDA) roller derby training scrimmages, when there is a shortage of NSOs.


By placing the Android device running this app on prominent display (and potentially connecting the device to a set of amplified speakers), this app is capable of running as a virtual jam timer, performing call off jam and timeout start / stop whistles and verbal warnings when 5 seconds of Line Up time is remaining (i.e. "5 seconds!").


Jam Timer tracks team timeouts and official reviews, ensuring that teams do not obtain more than they are entitled to. If a Delay of Game situation does arise, then Jam Timer automatically calls an official timeout immediately after the line up time has expired.


Jam Timer can be configured to prompt the user to put their Android device into Airplane mode at the start of the game, and also prompts the user to confirm if the user attempts to navigate away from the app mid-way through a game.


To help facilitate the elimination of a volunteer / NSO position to run Jam Timing, Jam Timer also supports the use of Bluetooth devices such as multimedia adapters and headsets as remote controls to access the various jam control, timeout and official review options. In the case of multimedia adapters, the Next / Previous Track and Play / Pause buttons are used; for supported headsets the volume control buttons are used.


Period, inter-period break, jam and line up time durations can all be adjusted to suit unusual local training conditions from the preferences menus. For more information on this and the use of bluetooth devices, please visit the developer's website link below.