I’ve finally managed to pull together a beta version of a little game timer application in Java.  There may still be one or two issues with it, so please download it and let me know where the bugs are, etc.  The application is very extensible. It is natively capable of using AGA/Japanese byoyomi (the default), Canadian byoyomi, Fischer time (with or without capping), and a simple main-time clock.  Checkout the website for more information.