Rhythm: metronome tempo tutor

The crash is fixed. The cause was a single sample in the sound bank: the grand piano's middle C looped past its own last frame, which is why it hit the piano sound hardest. The app no longer closes in the middle of an exercise. The line after an exercise now talks about the attempt, not about you. "A little off", "Running ahead", "Count out loud" — nothing there is an insult any more, and they are translated into every language the app speaks. Statistics has been rebuilt. At the top, the share you hit on target and one sentence about which side you miss on; below it the polyrhythm records — the fastest clean tempo you have held, for every ratio and every stage — which finally have somewhere to appear. Also fixed: the instrument you picked is saved again, and the timers of a stopped exercise no longer keep running.