AMATERAS

Smart alarm & sleep trackerAMATERAS

For a pleasant morning.Set it. Sleep.

Download on the App Store

Free · No ads · No account · iPhone (iOS 16.4 or later)

AMATERAS is a smart alarm for iPhone. Place your phone on the bedding, and it measures your movement with the accelerometer, estimates an easy moment to wake, and wakes you up to 5 minutes before your alarm time. If there is no such moment, it rings at your alarm time. It also records your estimated sleep depth every night.

A night of movement, and when it rings

EXAMPLE
A night of movement, and when it rings A line of body movement from 11 pm to 7 am. 6:45 to 7:00 is enlarged. The wake window is 6:55 to 7:00. 23:003:00 6:456:557:00 Movement
The window opens at 6:55. You keep moving, so it rings at about 6:57.
FEATURES

Features

Ringing at 6:59, before a 7:00 alarm
01

Wakes you at an easy moment

Up to 5 minutes before your alarm time, it rings at a moment you move. If you don't move, it rings at your alarm time.

Home screen: set to ring at 7:00 even if you forget
02

Rings even if you forget

Even if you forget to tap “Sleep”, it schedules an alarm that rings in silent mode (it may not ring with some device settings).

Morning screen: it will ring again at 7:00
03

Re-sleep guard

If you stop it before your alarm time, it rings again at your alarm time.

Night record with a sleep depth graph
04

Sleep records

Each night, it keeps a graph of sleep depth estimated from your movement. Records stay on your device.

Alarm sound settings
05

Wake-up melodies

Choose from 11 melodies. “Auto” picks one that fits your estimated sleep state.

  • Times for each weekday
  • Skip Japanese holidays
  • Snooze
  • 9 languages
HOW IT WORKS

How it works, and why

Being woken from deep sleep is known to make the grogginess right after waking (sleep inertia) stronger. So it aims for a moment when your sleep is estimated to be light.

  1. Measure

    The phone’s accelerometer measures movements such as turning over.

    25 times a second → summarized every 30 s

  2. Estimate

    You move more in light sleep and less in deep sleep. From how much and how often you move, it estimates sleep depth.

    compared with your usual movement

  3. Ring

    From 5 minutes before your alarm time, it rings when you keep moving. Otherwise, it rings at your alarm time.

    never in the first 3 hours of sleep

A phone alone cannot tell REM and non-REM sleep apart. The app does not name sleep stages; it only shows an estimate of depth from your movement. Also, there are no high-quality studies yet that test the effect of smart alarms themselves.

Sources: Tassi P, Muzet A. Sleep inertia. Sleep Med Rev. 2000;4(4):341–353. Hilditch CJ, McHill AW. Sleep inertia: current insights. Nat Sci Sleep. 2019;11:155–165.

More on how it works ›
HOW TO USE

How to use

Placement: put the phone on the bedding near your pillow, not under it On the bedding near the pillow Not under it
Your movement reaches the phone through the bedding.
  1. Set your wake-up timeYou can set it for each weekday.
  2. Tap “Sleep” before bedEven if you forget, the alarm still rings.
  3. Place it on the bedding near your pillowDon’t put it under the pillow. You can keep it charging.
  4. When it rings, swipe up to stopIf you stop it early, it rings again at your alarm time.
PRICE

Price

FreeNo ads, no in-app purchases, no account.
FIRST NIGHT

Check this first

  1. In Settings, use “Ring in 5 min” to check that it rings with the app closed and in silent mode.
  2. Allow alarms and notifications.
  3. Place the phone on the bedding near your pillow. Not under the pillow.
FAQ

FAQ

How does it estimate an easy moment to wake?

Body movements such as turning over are frequent in light sleep and rare in deep sleep. So it wakes you at a moment you move during the few minutes before your alarm time (5 minutes by default). It does not wake you because of movement within 3 hours of falling asleep. More

Why wake me in light sleep?

Being woken from deep sleep is known to make the grogginess right after waking (sleep inertia) stronger (Tassi & Muzet 2000; Hilditch & McHill 2019). However, there are no high-quality studies yet that test the effect of smart alarms themselves.

Can it tell REM and non-REM sleep apart?

No. It only shows an estimate of sleep depth from your movement.

The alarm did not ring

Check the alarm permission, the volume, and whether Bluetooth earphones are connected. On days with important plans, use another alarm as well.

Can it track with the screen off?

Yes, if you allow the microphone (no audio is saved). If you don’t, leave the screen on; it stays black.

How much battery does it use?

It depends on the device and settings, so keep the phone charging.

Where is my data stored?

On your device. Only if you turn on the optional data sharing for improvement is part of your records sent to our server (in the US) (Privacy Policy).

Can I move my records to a new phone?

The app has no transfer feature. Restoring from an OS backup may bring them over.

NEWS

Updates

  • We revised the Terms of Use and the Privacy Policy (effective October 30).
  • Version 1.0.6 is out. Long daytime tracking is left out of your record averages, and on iOS 18 and earlier it warns you when the alarm volume is low.
CONTACT

Contact

support@amateras-studio.com

Please put “Smart Alarm” in the subject.