Release notes

v5.0.0 – by 5 years: Ready for school

Counts to 10, writes some letters of their name and hops on one foot. Long-term support begins.

✨ Added – CDC: what most children do by 5 years

💛 Social/Emotional

• Follows rules or takes turns in games with other children
• Sings, dances, or acts for you
• Does simple chores, like matching socks or clearing the table

💬 Language/Communication

• Tells a story with at least two events
• Answers simple questions about a book or story
• Keeps a conversation going with more than three back-and-forth exchanges
• Uses or recognizes simple rhymes (bat–cat, ball–tall)

🧠 Cognitive

• Counts to 10
• Names some numbers between 1 and 5 when you point to them
• Uses words about time, like “yesterday”, “tomorrow”, “morning”
• Pays attention for 5 to 10 minutes during activities (screen time doesn’t count)
• Writes some letters of their name
• Names some letters when you point to them

🏃 Movement/Physical

• Buttons some buttons
• Hops on one foot

Source: CDC, Learn the Signs. Act Early. – 5 years (lightly paraphrased).

v4.0.0 – by 4 years: Imagination engine

Pretend play, four-word sentences and a strong interest in being the helper.

✨ Added – CDC: what most children do by 4 years

💛 Social/Emotional

• Pretends to be something else during play (teacher, superhero, dog)
• Asks to go play with children if none are around
• Comforts others who are hurt or sad
• Avoids danger, like not jumping from tall heights
• Likes to be a “helper”
• Changes behavior based on the place (library, playground)

💬 Language/Communication

• Says sentences with four or more words
• Says some words from a song, story, or nursery rhyme
• Talks about at least one thing that happened during the day
• Answers simple questions like “What is a coat for?”

🧠 Cognitive

• Names a few colors
• Tells what comes next in a well-known story
• Draws a person with three or more body parts

🏃 Movement/Physical

• Catches a large ball most of the time
• Serves food or pours water, with adult supervision
• Unbuttons some buttons
• Holds a crayon or pencil between fingers and thumb (not a fist)

🐛 Known issues (all normal)

• Lots of “why” questions. CDC suggests taking time to answer them, and it’s fine to say “I don’t know”. [source]

Source: CDC, Learn the Signs. Act Early. – 4 years (lightly paraphrased).

v3.0.0 – by 3 years: Conversation protocol

Supports back-and-forth conversation and the full who/what/where/why query set.

✨ Added – CDC: what most children do by 3 years

💛 Social/Emotional

• Calms down within 10 minutes after you leave, like at childcare drop-off
• Notices other children and joins them to play

💬 Language/Communication

• Has conversations with at least two back-and-forth exchanges
• Asks “who”, “what”, “where”, or “why” questions
• Says what action is happening in a picture or book
• Says their first name when asked
• Talks well enough for others to understand, most of the time

🧠 Cognitive

• Draws a circle when shown how
• Avoids touching hot objects, like a stove, when warned

🏃 Movement/Physical

• Strings items together, like large beads or macaroni
• Puts on some clothes by themselves
• Uses a fork

Source: CDC, Learn the Signs. Act Early. – 3 years (lightly paraphrased).

v2.6.0 – by 30 months: Pronoun support

Adds “I”, “me” and “we”. Vocabulary around 50 words. Jumping with both feet.

✨ Added – CDC: what most children do by 30 months

💛 Social/Emotional

• Plays next to other children and sometimes with them
• Shows you what they can do by saying “Look at me!”
• Follows simple routines when told, like clean-up time

💬 Language/Communication

• Says about 50 words
• Says two or more words together, with one action word, like “Doggie run”
• Names things in a book when you point and ask
• Says words like “I”, “me”, or “we”

🧠 Cognitive

• Uses things to pretend, like feeding a block to a doll
• Shows simple problem-solving, like standing on a stool to reach something
• Follows two-step instructions
• Shows they know at least one color

🏃 Movement/Physical

• Uses hands to twist things, like doorknobs or lids
• Takes some clothes off by themselves
• Jumps off the ground with both feet
• Turns book pages one at a time

🐛 Known issues (all normal)

• Toilet training: most children are not able to toilet train until 2 to 3 years old; starting too early can cause setbacks. [source]

Source: CDC, Learn the Signs. Act Early. – 30 months (lightly paraphrased).

v2.0.0 – by 2 years: Two-word queries

Breaking change: commands now accept two arguments (“More milk”). Running is enabled.

✨ Added – CDC: what most children do by 2 years

💛 Social/Emotional

• Notices when others are hurt or upset
• Looks at your face to see how to react in a new situation

💬 Language/Communication

• Points to things in a book when asked, like “Where is the bear?”
• Says at least two words together, like “More milk”
• Points to at least two body parts when asked
• Uses more gestures than waving and pointing, like blowing a kiss or nodding yes

🧠 Cognitive

• Holds something in one hand while using the other, like opening a container
• Tries to use switches, knobs, or buttons on a toy
• Plays with more than one toy at the same time, like toy food on a toy plate

🏃 Movement/Physical

• Kicks a ball
• Runs
• Walks (not climbs) up a few stairs, with or without help
• Eats with a spoon

🐛 Known issues (all normal)

• Children this age play next to each other but don’t yet know how to share or solve conflicts. [source]
• Appetite varies: toddlers don’t always eat the same amount or type of food each day. [source]

Source: CDC, Learn the Signs. Act Early. – 2 years (lightly paraphrased).

v1.6.0 – by 18 months: Autonomous mode

Walks unassisted, climbs furniture and explores away from you — while pinging home to check you’re still there.

✨ Added – CDC: what most children do by 18 months

💛 Social/Emotional

• Moves away from you, but looks to make sure you are close by
• Points to show you something interesting
• Puts hands out for you to wash them
• Looks at a few pages in a book with you
• Helps you dress them by pushing an arm through a sleeve or lifting a foot

💬 Language/Communication

• Tries to say three or more words besides “mama” or “dada”
• Follows one-step directions without gestures, like “Give it to me”

🧠 Cognitive

• Copies you doing chores, like sweeping
• Plays with toys in a simple way, like pushing a toy car

🏃 Movement/Physical

• Walks without holding on to anyone or anything
• Scribbles
• Drinks from an open cup, sometimes spilling
• Feeds themselves with fingers
• Tries to use a spoon
• Climbs on and off a couch or chair without help

🐛 Known issues (all normal)

• Tantrums are still normal and should become shorter and less frequent over time. [source]
• Toilet training: most children are not successful until 2 to 3 years old. Ask your child’s doctor about readiness. [source]

Source: CDC, Learn the Signs. Act Early. – 18 months (lightly paraphrased).

v1.3.0 – by 15 months: Walking (beta)

First steps without a handrail. Vocabulary API expanded beyond “mama” and “dada”.

✨ Added – CDC: what most children do by 15 months

💛 Social/Emotional

• Copies other children while playing
• Shows you an object they like
• Claps when excited
• Hugs a stuffed doll or other toy
• Shows you affection (hugs, cuddles, or kisses)

💬 Language/Communication

• Tries to say one or two words besides “mama” or “dada”, like “ba” for ball
• Looks at a familiar object when you name it
• Follows directions given with both a gesture and words
• Points to ask for something or to get help

🧠 Cognitive

• Tries to use things the right way, like a phone, cup, or book
• Stacks at least two small objects, like blocks

🏃 Movement/Physical

• Takes a few steps on their own
• Uses fingers to feed themselves some food

📊 Typical windows (WHO)

• Walking alone: usually between 8.2–17.6 months

Range = 1st to 99th percentile of healthy children in the WHO Motor Development Study.

🐛 Known issues (all normal)

• Tantrums: CDC calls them normal at this age, more likely when tired or hungry, and says they should get shorter and less frequent with age. [source]
• Early words are not complete (“ba” for ball). Repeating the full word back helps. [source]

Source: CDC, Learn the Signs. Act Early. – 15 months (lightly paraphrased).

v1.0.0 – month 12: First stable release

End of year one: pulls up to stand, walks holding on to furniture and calls you “mama”, “dada” or another special name.

✨ Added – CDC: what most children do by 12 months

💛 Social/Emotional

• Plays games with you, like pat-a-cake

💬 Language/Communication

• Waves “bye-bye”
• Calls a parent “mama”, “dada”, or another special name
• Understands “no” (pauses briefly or stops)

🧠 Cognitive

• Puts something in a container, like a block in a cup
• Looks for things they saw you hide, like a toy under a blanket

🏃 Movement/Physical

• Pulls up to stand
• Walks while holding on to furniture
• Drinks from an open cup while you hold it
• Picks things up between thumb and pointer finger

📊 WHO motor windows at 11–12 months

• Hands-and-knees crawling: 5.2–13.5 months (open)
• Standing with assistance: 4.8–11.4 months (closes this month – 99th percentile reached)
• Walking with assistance: 5.9–13.7 months (open)
• Standing alone: 6.9–16.9 months (open)
• Walking alone: 8.2–17.6 months (open)

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

🐛 Known issues (all normal)

• New foods may be rejected on the first try. CDC suggests offering them again and again. [source]

💡 Tip

Look after yourself, physically and emotionally. Parenting is hard work, and it is easier to be a loving parent when you feel good too.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

Source: CDC, Learn the Signs. Act Early. – 12 months (lightly paraphrased).

v0.11.0 – month 11: Patch: pre-release

No CDC checklist this month. One more patch before the 12-month checklist.

✨ Added

No CDC milestone checklist exists for this month (CDC publishes checklists for 2, 4, 6, 9 and 12 months), so no milestones are listed here on purpose.

📊 WHO motor windows at 10–11 months

• Hands-and-knees crawling: 5.2–13.5 months (open)
• Standing with assistance: 4.8–11.4 months (open)
• Walking with assistance: 5.9–13.7 months (open)
• Standing alone: 6.9–16.9 months (open)
• Walking alone: 8.2–17.6 months (open)

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

💡 Tip

Sing to your baby and play music; CDC says it supports brain development.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

v0.10.0 – month 10: Patch: first window closes

No CDC checklist this month. The WHO window for sitting without support closes (99th percentile).

✨ Added

No CDC milestone checklist exists for this month (CDC publishes checklists for 2, 4, 6, 9 and 12 months), so no milestones are listed here on purpose.

📊 WHO motor windows at 9–10 months

• Sitting without support: 3.8–9.2 months (closes this month – 99th percentile reached)
• Hands-and-knees crawling: 5.2–13.5 months (open)
• Standing with assistance: 4.8–11.4 months (open)
• Walking with assistance: 5.9–13.7 months (open)
• Standing alone: 6.9–16.9 months (open)
• Walking alone: 8.2–17.6 months (open)

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

💡 Tip

Read to your baby – it helps them understand language and sounds.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

v0.9.0 – month 9: Object permanence

Things that leave the screen no longer cease to exist. Stranger detection enabled by default.

✨ Added – CDC: what most children do by 9 months

💛 Social/Emotional

• Is shy, clingy, or fearful around strangers
• Shows several facial expressions (happy, sad, angry, surprised)
• Looks when you call their name
• Reacts when you leave (looks, reaches for you, or cries)
• Smiles or laughs at peek-a-boo

💬 Language/Communication

• Makes lots of different sounds like “mamamama” and “bababababa”
• Lifts arms up to be picked up

🧠 Cognitive

• Looks for objects dropped out of sight (like a spoon or toy)
• Bangs two things together

🏃 Movement/Physical

• Gets to a sitting position by themselves
• Moves things from one hand to the other
• Uses fingers to “rake” food towards themselves
• Sits without support

📊 WHO motor windows at 8–9 months

• Sitting without support: 3.8–9.2 months (open)
• Hands-and-knees crawling: 5.2–13.5 months (open)
• Standing with assistance: 4.8–11.4 months (open)
• Walking with assistance: 5.9–13.7 months (open)
• Standing alone: 6.9–16.9 months (open)
• Walking alone: 8.2–17.6 months (opens this month)

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

🐛 Known issues (all normal)

• Shyness or clinginess around strangers is listed by CDC as an expected milestone at this age, not a bug. [source]
• Dropping things over and over is a game. Handing it back helps them learn. [source]
• Not every child crawls on hands and knees: in the WHO study, 4.3% of children never did. [source]

💡 Tip

Once your baby is on the move and grabbing things they shouldn’t, redirect with a toy or move them somewhere safe.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

Source: CDC, Learn the Signs. Act Early. – 9 months (lightly paraphrased).

v0.8.0 – month 8: Patch: window update

No CDC checklist this month. Every WHO window except walking alone is now open.

✨ Added

No CDC milestone checklist exists for this month (CDC publishes checklists for 2, 4, 6, 9 and 12 months), so no milestones are listed here on purpose.

📊 WHO motor windows at 7–8 months

• Sitting without support: 3.8–9.2 months (open)
• Hands-and-knees crawling: 5.2–13.5 months (open)
• Standing with assistance: 4.8–11.4 months (open)
• Walking with assistance: 5.9–13.7 months (open)
• Standing alone: 6.9–16.9 months (open)

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

💡 Tip

Cut food into small bites and keep small toys and other easy-to-swallow things away to prevent choking.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

v0.7.0 – month 7: Patch: standing update

No CDC checklist this month. The WHO window for standing alone opens.

✨ Added

No CDC milestone checklist exists for this month (CDC publishes checklists for 2, 4, 6, 9 and 12 months), so no milestones are listed here on purpose.

📊 WHO motor windows at 6–7 months

• Sitting without support: 3.8–9.2 months (open)
• Hands-and-knees crawling: 5.2–13.5 months (open)
• Standing with assistance: 4.8–11.4 months (open)
• Walking with assistance: 5.9–13.7 months (open)
• Standing alone: 6.9–16.9 months (opens this month)

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

💡 Tip

Feed slowly and patiently. Offer new tastes without forcing, and watch for signs your baby is still hungry or full.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

v0.6.0 – month 6: Laughter shipped

Full laugh support lands. Everything is now tested by putting it in the mouth.

✨ Added – CDC: what most children do by 6 months

💛 Social/Emotional

• Knows familiar people
• Likes to look at self in a mirror
• Laughs

💬 Language/Communication

• Takes turns making sounds with you
• Blows “raspberries” (sticks tongue out and blows)
• Makes squealing noises

🧠 Cognitive

• Puts things in mouth to explore them
• Reaches to grab a toy they want
• Closes lips to show they don’t want more food

🏃 Movement/Physical

• Rolls from tummy to back
• Pushes up with straight arms when on tummy
• Leans on hands to support themselves when sitting

📊 WHO motor windows at 5–6 months

• Sitting without support: 3.8–9.2 months (open)
• Hands-and-knees crawling: 5.2–13.5 months (opens this month)
• Standing with assistance: 4.8–11.4 months (open)
• Walking with assistance: 5.9–13.7 months (opens this month)

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

💡 Tip

CDC says breast milk covers a baby’s needs for about the first 6 months; between 6 and 12 months, healthy solid foods bring new tastes and textures while breast milk stays important. Ask your paediatrician when to start.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

Source: CDC, Learn the Signs. Act Early. – 6 months (lightly paraphrased).

v0.5.0 – month 5: Patch: new windows

No CDC checklist this month. More WHO motor windows open – windows, not deadlines.

✨ Added

No CDC milestone checklist exists for this month (CDC publishes checklists for 2, 4, 6, 9 and 12 months), so no milestones are listed here on purpose.

📊 WHO motor windows at 4–5 months

• Sitting without support: 3.8–9.2 months (open)
• Standing with assistance: 4.8–11.4 months (opens this month)

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

💡 Tip

Play when your baby is alert and relaxed, and take a break when they look tired or fussy.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

v0.4.0 – month 4: Audio output: cooing

Two-way audio is in beta. Smiles are now sent proactively instead of only on request.

✨ Added – CDC: what most children do by 4 months

💛 Social/Emotional

• Smiles on their own to get your attention
• Chuckles (not yet a full laugh) when you try to make them laugh
• Looks at you, moves, or makes sounds to get or keep your attention

💬 Language/Communication

• Makes cooing sounds like “oooo” and “aahh”
• Makes sounds back when you talk to them
• Turns head towards the sound of your voice

🧠 Cognitive

• If hungry, opens mouth on seeing breast or bottle
• Looks at their hands with interest

🏃 Movement/Physical

• Holds head steady without support when held
• Holds a toy when you put it in their hand
• Swings an arm at toys
• Brings hands to mouth
• Pushes up onto elbows/forearms when on tummy

📊 WHO motor windows at 3–4 months

• Sitting without support: 3.8–9.2 months (opens this month)

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

🐛 Known issues (all normal)

• Putting safe things in the mouth is how babies explore and learn. Only let them mouth things that are not sharp, hot, or small enough to choke on. [source]

💡 Tip

Floor time counts: moving around on the floor helps babies get strong and explore. Try not to leave them in swings, bouncers or strollers for long stretches.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

Source: CDC, Learn the Signs. Act Early. – 4 months (lightly paraphrased).

v0.3.0 – month 3: Maintenance release

No CDC checklist this month; no WHO motor windows open yet.

✨ Added

No CDC milestone checklist exists for this month (CDC publishes checklists for 2, 4, 6, 9 and 12 months), so no milestones are listed here on purpose.

📊 WHO motor windows at 2–3 months

No WHO window is open yet – the earliest (sitting without support) opens at 3.8 months.

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

💡 Tip

When your baby makes a sound, repeat it back and add a word or two. It helps them learn language.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

v0.2.0 – month 2: Hello, world

First public build. Mostly runs on milk and sleep, but the UI is starting to respond to input.

✨ Added – CDC: what most children do by 2 months

💛 Social/Emotional

• Calms down when spoken to or picked up
• Looks at your face
• Seems happy to see you when you walk up
• Smiles when you talk to or smile at them

💬 Language/Communication

• Makes sounds other than crying
• Reacts to loud sounds

🧠 Cognitive

• Watches you as you move
• Looks at a toy for several seconds

🏃 Movement/Physical

• Holds head up when on tummy
• Moves both arms and both legs
• Opens hands briefly

📊 WHO motor windows at 1–2 months

No WHO window is open yet – the earliest (sitting without support) opens at 3.8 months.

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

🐛 Known issues (all normal)

• Crying is often worse in the first few months of life, but it gets better. Never shake a baby. If you get upset when they cry, put the baby in a safe place, walk away, and check on them every 5–10 minutes. [source]

💡 Tip

Talk to your baby a lot; CDC notes that babies find a parent’s voice calming.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.

Source: CDC, Learn the Signs. Act Early. – 2 months (lightly paraphrased).

v0.1.0 – month 1: Initial commit

Newborn firmware boots. No CDC checklist for month 1 and no WHO motor windows open yet.

✨ Added

No CDC milestone checklist exists for this month (CDC publishes checklists for 2, 4, 6, 9 and 12 months), so no milestones are listed here on purpose.

📊 WHO motor windows at 0–1 months

No WHO window is open yet – the earliest (sitting without support) opens at 3.8 months.

Window = 1st to 99th percentile of age at achievement among healthy children in the WHO Motor Development Study (WHO MGRS 2006, PDF). Windows are wide and overlap; they are not deadlines.

💡 Tip

Put your baby down to sleep on their back every time – CDC recommends this to lower the risk of SIDS.

Tip based on CDC, Positive Parenting Tips: Infants (0–1 years), rewritten in our own words.