A glowing amber moon hand-painted in watercolor, with a small child silhouette gazing up from a hill below.

The guardian of gentle dreams.

A picture-book bedtime app for ages 3 to 7. 100% offline. Zero accounts. Zero tracking.

Spring 2026

Why parents choose Baku

A cream-colored paper airplane gliding past a small amber moon.

Powered by Gemma 4 · 100% offline

A 1.5 GB on-device language model runs entirely on your iPhone's neural engine. No cloud, no servers, no API calls. Airplane mode works forever.

A small wooden treasure chest with a brass padlock under amber starlight.

Zero data leaks · Zero tracking

Your child's voice never leaves the device. No accounts, no analytics, no third-party SDKs, no advertising. The phone in your hand is the only place anything lives.

A child in cream pajamas walking toward a window with a teddy bear.

Safe for ages 3-7

Every story passes a 12-language safety filter. No violence, no fear, no scary monsters. Every tale closes with a child falling asleep smiling.

Three children of different ethnicities sitting in a circle under a giant amber moon.

Three native languages

English, Simplified Chinese, Spanish. Each language has its own voice and a separate library — never machine-translated.

A note from the maker

A person at a wooden writing desk by a moonlit window, seen only as a silhouette and hands writing in a notebook.

I'm Jingyang. I'm an uncle in California. I built Baku because my niece asked me one night for "a story about a sleepy dragon," and I realized every existing bedtime app on her iPad was either an ad-funnel, an account form, or a content delivery pipeline.

So I spent the last year writing one that wasn't.

Baku runs entirely on your iPhone. The AI that writes the stories is a small language model that fits in 1.5 GB of memory. The voice that reads them is Apple's own. Your child can whisper the wildest idea and it never leaves the device.

I'm one person. There is no team, no investors, no roadmap to subscription dark patterns. There is just me, my niece, and a moon I painted for her.

A small girl with twin braids in cream pajamas reading a picture book on her bed.

────── The numbers ──────

170
Swift files
34
tests
265
hand-crafted stories
10
guided meditations
10
classic lullabies
7
ambient sounds
0
servers
0
trackers
0
analytics SDKs

No mailing list. No tracking. No "join the beta."

Just check back this Spring.

— Jingyang Ye

Made with care in California 🌙

What's inside

A small friendly dragon curled up sleeping on a cream pillow under an amber moon.
An open storybook with amber stars floating up from its pages.

AI bedtime stories

A small on-device language model weaves a new story every night, guided by a single word your child whispers.

A leaning stack of children's picture books in cream, amber, and dusty blue.

264 hand-crafted preset stories

When you don't want to wait. Each story illustrated and read in your child's chosen language.

A small child in silhouette sitting cross-legged with a soft mist cloud rising from their breath.

Guided meditation & breathing

10 short exercises to help wound-up children wind down.

A constellation in the night sky shaped like a sleeping curled-up cat.

Lullaby Sky

A constellation of 10 classic lullabies, sung in three languages by Apple's premium voices.

Rain drops on a window seen from inside a cozy room with a teacup.

Ambient sounds

Rain. Ocean. Forest. Crickets. Night wind. A music box. With a sleep timer.

Frequently asked

A steaming teacup next to an open notebook on a wooden table at night.
Does it really work offline?

Yes. Once the language model is downloaded once (on the first run, with WiFi), the app never makes another network request. You can put your phone in Airplane Mode forever and Baku still works.

Is it safe for my 4-year-old?

Stories are filtered through a 12-language safety system that blocks any violent, scary, or sad content before it ever reaches your child's ears. Parental approval is required before the AI mode can be unlocked.

How does the AI work?

A small language model called Gemma 4 (about 1.5 GB) runs entirely on your iPhone's neural engine. It's the same kind of technology that powers ChatGPT, but smaller, simpler, and 100% local.

What languages does it speak?

English, Simplified Chinese, and Spanish. Each language has its own dedicated voice and a separate library of preset stories — no machine translation.

What's the price?

A one-time purchase of $19.99 unlocks everything forever. There is also a $3.99/month subscription if you prefer to pay slowly. Either way: no ads, no in-app upgrades, no dark patterns.

Who built this?

One person — me, Jingyang Ye, in California. There is no company, no investors, no team. Just an uncle and a moon.