I loved your metronomes, and I think it would be useful having a visual bar that gets full at each beat, just to mark the beat time. I'm training at a REALLY low speed, and I lose track all the time because of the long wait to the next beat (I'm training at 20 bpm) ;)
Obs. I'm training finger control, so it's faster to achieve it by training at this awful speed rather than higher ones (ironic, really).
Really good job