SleepTyme is the smart alarm that fades from a whisper to full volume so you wake gently — calibrated to your 90-minute sleep cycles.
Free Night Sleep calculator. Smart alarm, Apple Health, Nap mode & all ages unlocked with a one-time $1.99 SleepTyme Pro purchase. No subscription, no ads.
SleepTyme combines a sleep cycle calculator with a gradual-fade wake-up alarm. The result is the gentlest morning routine your iPhone can deliver.
The chime starts at true silence and ramps up over 30 seconds using a cubic ease-in curve — barely audible for the first 10 seconds, then gently rising. You wake the way nature intends.
Enter a bedtime, get four ranked wake times: Optimal, Great, Good, Minimum. Each shows your total sleep, cycle count, and a visual breakdown of deep, REM, and light sleep phases.
Five science-backed nap durations: 20-min Power Nap, 30-min Memory Boost, 90-min Full Cycle, 120-min Recovery. Plus a red Danger Zone warning at 45 minutes — when waking interrupts deep sleep.
Sleep cycles differ. Adults run 90 min with 14-min sleep onset. Teens shift later with a 20-min latency. Infants use 50-min REM-dominant cycles. SleepTyme tunes its math to whoever's sleeping.
Need an alarm for a specific time, not a calculated wake? Tap the alarm icon, spin the wheel, done. Perfect for naps, timers, or "wake me in 20 minutes."
Opt-in. Read your recent sleep history to track averages; write your planned sleep schedule so other apps and Apple's own Bedtime see it. Local-only. Always.
SleepTyme strips the friction out of "the alarm." No accounts, no setup, no subscription. Just sleep.
Open the app. SleepTyme grabs the current time as your bedtime, or tap "Pick a Time" to enter a custom one. Four wake times appear, ranked by quality.
Tap "Set Alarm" on any wake time. A green banner confirms the alarm is set and tells you it'll fade in over 30 seconds.
Lock your phone. SleepTyme keeps the alarm engine alive overnight via background audio. At wake time, the chime fades from silence to full volume.
Sleep moves through ~90-minute cycles. Inside each cycle, you cross light sleep, deep sleep, REM, and back to light. The end of a cycle is the easiest moment to wake — your brain is already half-aware.
Approximate adult proportions
If your alarm hits the middle of deep sleep, your brain is forced out of slow-wave sleep abruptly — that's sleep inertia, the groggy 30 minutes after waking. SleepTyme times your alarm to land on the LIGHT portion at the end of a cycle. Wake there, and you feel rested instantly.
| Infant (0-12 mo) | Teen (13-17) | Adult (18+) | |
|---|---|---|---|
| Cycle length | 50 min | 90 min | 90 min |
| Fall-asleep latency | 5 min | 20 min | 14 min |
| Deep sleep % | 25% | 25% | 22% |
| REM sleep % | 50% | 25% | 28% |
| Recommended hours | 12-16h | 8-10h | 7-9h |
SleepTyme's Apple Watch companion runs the same engine on a smaller canvas. Glance at your wrist, tap "Wake Times," and your four optimal times appear instantly. No phone required.
The alarm itself stays on iPhone — the Watch speaker can't do a 30-second fade gracefully. But your watch gets a strong haptic when the alarm fires, matching the pattern Apple uses for Bedtime.
Join the TestFlight beta to try SleepTyme on your iPhone before the App Store launch. Free during beta. No payment required.