PowerNap: Nap Timer & Alarm

Your lunch break ends at a fixed time. So the real question isn't "how long should I nap" — it's "by when should I lie down?"

PowerNap is a nap timer built around the watch on your wrist. It estimates sleep onset from heart rate and motion. It starts with a standard 15-minute suggestion. After 5 valid assessments, it uses your history to suggest a duration from 10 to 20 minutes and works backwards from your fixed wake-up time to tell you when to lie down.

HOW IT WORKS

1. Set your wake-up time (e.g. 12:55)
2. Lie down by the suggested time and tap Start Nap on your watch
3. Heart rate + stillness estimate sleep onset — no tapping needed
4. Confirm whether you slept and rate grogginess, then rate return-to-work readiness about 30 minutes later After 5 assessed naps, history-based suggestions begin.

MADE FOR YOUR WRIST

• PowerNap estimates sleep onset from a sustained heart-rate drop and continuously observed stillness. Resting while awake can still resemble sleep.
• Last night's sleep duration, resting heart rate and HRV shown as reference information
• Backup notifications on both watch and iPhone
• Without sufficient heart-rate data, no sleep estimate is made; the scheduled alarm still works.

TRACK AND UNDERSTAND

• Every nap recorded automatically: estimated onset and sleep duration, heart-rate curve
• Wake-up and 30-minute assessments, weekly charts and start-time patterns
• Insights based on your own answers and history
• The heart-rate graph for your latest completed, non-cancelled nap is included without a purchase. Access moves to the next completed nap; older graphs require Pro.
• Sleep totals and averages include estimates only when you confirm that you slept. No, unsure and unanswered records are excluded.

POWERNAP PRO (ONE-TIME PURCHASE) A one-time Pro purchase unlocks history-based suggestions, older heart-rate graphs, history charts and insights. No subscription. With Pro, optionally wake before the scheduled alarm when the estimated sleep duration reaches your target.

PRIVATE BY DESIGN Nap, heart-rate and assessment records are processed on your devices and are not sent to our servers. No ads, tracking or accounts. Purchases communicate with Apple through StoreKit.

• Requires a watch running watchOS 10 or later
• PowerNap is not a medical device and is not intended to diagnose or treat any condition. Sleep onset is estimated from heart rate and motion.