Coozy, baby milestone tracker
I designed Coozy, a baby milestone tracker, end to end and reworked its onboarding to answer a parent's worry first, which lifted trial starts and paid conversions.
Context
Parents weren't short of information. They were short of calm. Coozy's job was to make ordinary development feel ordinary again.
Books and blogs were slow, social media hard to trust, and reading more made parents more anxious.
A team of three
The founder, a developer and I shipped V1 on Android in a month.
Health, no clinic
One pediatric reviewer, and everything safe to read at 2 AM.
What I shipped
A calm app for milestones, leaps and play. As Rabbit Apps' only designer, I made the product and the brand.
Coozy AI, briefly
Since September 2025, every answer shows its sources and points to the pediatrician.
Memories
A milestone can keep a photo, on a timeline by age.
Settings and profile
Profile, support and a community banner.
The brand
Mark, palette, type and illustrations. The mock-up babies are AI-generated.
Onboarding
The first version converted badly: it opened with facts and asked the parent nothing. So V2 answers the worry before showing the feature.
Priming, then the paywall
Results about their own baby first, then hold to commit, before the price.
Trial starts and paid conversions went up, so the trade-off, a longer onboarding, paid off.
Milestones in ranges
A milestone list can read like a report card. So Coozy's 150+ CDC-based milestones come in gentle age ranges. Every answer is allowed.
Leaps
Fussy weeks feel random when you're in them. Coozy tracks the ten leaps from birth to 20 months, and says when one is coming.
Learn once, then plan
The first visit explains leaps; then a timeline of all ten.
I called them leaps, not growth spurts: easy to remember and to brand.
Brand and store
I made Coozy's look, from a mood board to icons and handmade babies, to hold up in the store and in ads.
Impact
Parents came to track, not to chat. The reviewed content did the reassuring.
- $5KMRR within two months of launch, per the founder
- 4.8★App Store, 301 ratings (Nov 2026)
- 4.4★Google Play, 777 reviews (Nov 2026)
I cut the rating prompt to three choices. Replies were mostly about feeling calmer.
It keeps my anxiety at bay, assures me everything is normal with my baby.
In 614 comments, the AI comes up about three times; milestones 26, leaps 20.
The AI was the supporting act; the content was the band.
Reflection
Parents lived in the milestones and leaps, so next time I'd put the AI where they already are.
Build the AI into the milestones. It lived in its own tab, away from the cards and alerts parents used.
Grow the activities. Each video was hand-animated, so the library stayed small. Generative video could make it far bigger.