Well, I was goofing around on a free iPad app I have called Synth. It has a metronome on it, and there's an interesting setting that allows you to set the beat by tapping it, and adjusts it relative to the time between your last note. I'd never seen one of these before. It displays the BPM as you tap it, so I kept trying to keep it on a single BPM. It was very difficult, it usually fluctuated 1-3 beats off each time I hit, going around 90. Anyone else seen this kind of tech before? How do you fair while trying this?