29 Signals Your iPhone Already Knows About Your Stress

We built Respiro because of a question: what if your phone could notice you're stressed before you do? Turns out, it can. Without a smartwatch. Without asking you to check in. Just by listening to the signals your phone already collects. The 29 Signals Your iPhone generates data constantly. Most apps ignore it. We don't. Here's what we read: From motion sensors (accelerometer + gyroscope): How steady your hands are when holding your phone Your walking pattern changes (stressed people walk differently) How much you fidget while sitting Sudden posture shifts From usage patterns: Screen unlock frequency (stress = checking phone more) App switching speed (scattered attention = elevated stress) Typing speed and error rate Time between notifications and responses From health data (with permission): Heart rate variability (HRV) — the gold standard for stress Resting heart rate trends Sleep stages and interruptions Respiratory rate during sleep Blood oxygen patterns From context: Calendar dens