Baby development, honestly

The first two years come in waves. Each one ends.

Six waves from 0 to 24 months, each with an end in sight. Little Waves tells you what is normal, what may be coming and when it usually ends, from independent research and from what you notice in your own baby.

Works on the due date alone. Logging never unlocks anything; it only sharpens what you see.

A mother in a cream sweater holds her baby by a sunlit window; the baby looks up at her and she smiles.
Calm Waters
  • Six waves, 0 to 24 months

    Wide stretches with a documented end, never a date on a calendar.

  • Detected in your logs

    A rough stretch becomes your baby’s own Swell only from what you noticed.

  • Every claim shows its source

    Each card carries a plain-language citation you can read.

A pregnant woman in a linen dress walks barefoot along a calm shoreline at sunrise, one hand on her belly.

Before the first wave

It begins with the due date.

Enter the due date and everything runs: which wave is open, what tends to appear, when most babies are through it, what opens next. Born early? The early waves count from the due date, as the research on preterm babies shows.

You do not have to log a thing. Logging never unlocks anything; it only sharpens what you see.

Forming Calm Waters

How it works

Three things Little Waves does, in your baby’s own time.

Waves you can see coming. A Swell we only ever detect. Firsts that do something. And calm, by design.

1Waves

Six Waves, each with an end in sight

The first two years bring six developmental waves: The Crying Peak, First Smiles, The Sleep Switch, Stay Close, Big Moves and Little Me. Each is a wide stretch with a documented end, never a date on a calendar. Two can be open at once, and most of the timeline is calm.

Forming After the Wave
A mother and her baby lie face to face on a white bed, both laughing.

The first two years

Six wide waves. Two can be open at once. Most of the timeline is calm.

The six waves across the first 24 months, drawn as wide stretches; two can overlap, and most of the timeline is calm.
  1. The Crying PeakIt peaks, then it falls.
  2. First SmilesWaking up to you.
  3. The Sleep SwitchA switch to grown-up sleep, not a step back.
  4. Stay CloseYour baby’s message, told plainly.
  5. Big MovesOpens with the first crawl or steps, whenever they come.
  6. Little MeA person arriving.
A mother in a soft sweater cradles her sleeping, swaddled newborn in a nursery armchair.

2The Swell

A rough stretch? Detected in your logs, never scheduled.

Log today’s signals in about twenty seconds: crying, clinginess, sleep, feeding. Two signal days inside an open wave turn it into your baby’s own Swell, with a known start and its usual end in view. We never assert a phase from a calendar, and never without what you noticed.

The Swell It settles
A laughing mother kneels on a blue rug with her arms open as her baby crawls toward her.

3Firsts & calm

Firsts that do something. And calm, by design.

First smile, first point, first crawl, first steps. Every First shows its full normal range, from CDC and WHO milestone data, never an average. Log the first crawl or the first steps and Big Moves opens at the true moment, whenever it comes.

When nothing is forming, we say so. Calm Waters is a state we designed, not an empty screen.

Firsts Calm Waters

Why today?

Rough night? Real answers, with sources.

Why today? is the screen for 3 a.m. In ten seconds it tells you what tends to be happening at this point, what tends to help and when it usually passes. Every answer carries a plain-language citation, in the Night Tide appearance, made for 3 a.m.

1Nothing unusual

Rough days cluster and pass without a cause. In Little Waves that is a first-class answer, not a fallback.

Why we say this

2Earlier or later than other babies?

Answered with the full normal range for each First, never with an average and never with a verdict.

Why we say this

A mother sits under a warm lamp at night holding her phone, looking toward her baby asleep in a bedside crib.

Trust

What we won’t tell you.

A page in Little Waves lists what we refuse to claim. The short version:

A mother holds hands with her toddler, who takes wobbly steps at the water’s edge on a calm beach.
  1. No fixed weeks

    We never count down to a named day.

    In the research we reviewed, no independent study confirms developmental shifts at fixed weeks after birth. So we count down only to a wave opening, and a wave is always a wide stretch.

  2. No verdicts

    Full ranges, never an average.

    Every First shows the whole normal range from CDC and WHO milestone data. Sequence matters; dates on their own do not. Normal without a cause is a real answer here.

  3. No phase without your signals

    The Swell is detected, not scheduled.

    We never say your baby is in a rough stretch because a calendar says so. The Swell appears only when your own logs show it, and it always carries its end.

  4. No claim without a source

    Every card cites its source.

    Each card carries a “Why we say this” link to the research it rests on, in plain language. If we cannot cite it, we do not say it.

Sources for this page: our evidence base, including de Weerth & van Geert 1998 and Vermillet et al. 2022 on the absence of developmental shifts at fixed weeks; de Weerth, van Geert & Hoijtink 1999, Adolph et al. 2008 and Hörnell et al. 1999 on rough days that cluster and pass without a cause; WHO 2006 and Zubler et al. 2022 (CDC) for milestone ranges; Barr 1996 and Wolke et al. 2017 on the early crying curve and its timing from the due date; Mindell et al. 2016 on sleep changes being individual rather than universal. Every card cites its own.

The Book of Firsts

Two years, every First, one book. Always yours.

A diary of notes, sleep and feeding, written from what you log. After every wave, a recap of what actually happened.

  • Readable whatever your subscription status, and you can share a copy out of the app as text at any time. Nothing is ever locked away.
  • Child photos stay on your phone. In this first version they are not backed up or synced anywhere.
  • As many children as you have, in one book each.
A mother in a soft headscarf sits on a sofa with her one-year-old on her lap, looking at a small photo book together.
A mother with her baby in a fabric carrier walks along a wooden boardwalk beside a calm sea in the early morning.
Calm Waters

Most of the timeline is calm.

When nothing is forming, we say so, and we leave you alone. Notifications are few and every one carries information: a wave opens, a swell is detected, a swell settles, a recap is ready.

Plans

Plain prices. Nothing held back.

Everything you see today stays free: the waves, the Firsts, Why today?, the diary and the Book of Firsts. A subscription adds the personal layer: the swell detected in your logs with its end in view, personal recaps and the Activities. If the subscription ends, everything you entered stays readable, and you can still share a copy out of the app as text.

Free

  • The waves, from the due date, and countdowns to a wave opening
  • The Firsts, with their full normal ranges
  • Why today?
  • Logging, the diary and the Book of Firsts, always readable and shareable as text

Little Waves Premium

The subscription adds the personal layer:

  • The Swell, detected in your logs, with its end in view
  • Personal recaps
  • The Activities
  1. 1 month

    $4.99

    $4.99 a month

    Renews monthly. Cancel any time in your Apple Account settings.

  2. 3 months

    $9.99

    $3.33 a month

    Saves 33% against monthly

    Renews every 3 months. Cancel any time in your Apple Account settings.

  3. 24 months

    $34.99

    $1.46 a month

    Saves 71% against monthly

    One payment. Does not renew.

Prices shown are for the App Store in the United States; every other country sees its own price in Little Waves. Payment is charged to your Apple Account at confirmation of purchase. A renewing plan renews unless auto-renew is turned off at least 24 hours before the current period ends.

Get Little Waves on the App Store