Metronome Bounce on App Store - I don't know the author - looks good from the video.
This may be useful if you want a minimal metronome with bounce visuals for ipad / iphone,
I don't know the author but it looks well designed from the video. It is exactly the sort of thing I hope to program first of all if / when I get a chance to do a multi-platform version of Bounce Metronome.
For Windows and On-line metronomes
I maintain a list of some of the other software metronomes available here:
Some of the Other Software Metronomes Available