GooseNeck taps the motion sensors Apple ships in every Apple Silicon MacBook for fall detection but never exposed to developers. Calibrate your baseline once, then a colored dot in the Dynamic Island stays green while you sit straight and turns red as you drift; smart break reminders count active typing time, not wall clock, so a 5-minute coffee doesn’t reset your session. $14.99 one-time, M1 or newer only — direct download because private APIs disqualify it from the App Store.