Nice. I built something similar. Apart from mine being much less polished, I also didn't include the keyboard; just the name of the chord. That way I could practice the chord shapes that I had learned (or look them up if I forgot).

With the keyboard there, I feel like I'm practicing copying that, instead of learning the chords. Especially with the timer ticking. I'd be curious to hear about your reasons for putting it there. Possibly your goal is very different from mine.