A metronome you feel. Silent haptic time on your wrist, precise to about a millisecond, that keeps ticking when your arm drops to play. Turn the crown for tempo, tap the number to set it by feel, press begin. No phone needed.
Questions, bugs, or ideas: email pearcityguitars@gmail.com and put "Still Beat" in the subject line. I read everything.
Five haptic styles from a whisper to a knock — sharp, the default, uses the same haptic Apple built to reach you mid-stride. The watch shows its own live timing error, so precision is a number you can read, not a claim. If beats feel faint, snug the band a notch.