Android now · iPhone soon · your own API key

A book about exactly your thing, at exactly your level.

MetaBook interviews you about a topic, proposes chapters you can edit, and writes the book on your phone, one chapter at a time. When a passage lands badly, hold it and say what is wrong with it.

$5 once on Google Play. Then your own OpenRouter key, at cost — about 25¢ for an eight-chapter book. No subscription.

Get it onGoogle Play iPhone · coming soonJoin the waitlist

Not sure yet? Read the sample book first.

No account, no server of ours, no analytics. Every model call goes from your phone to your provider, and says what it will cost before it runs.

New book 2 / 3

Your brief

Time zones, and why they are hard

English Non-fiction

How much do you already know about the way the earth’s rotation is actually measured?

Almost nothing The rough idea I work with it

From question three on, you can stop the interview whenever you have said enough.

Enough questions Continue

Outline

Six chapters · yours to edit

Time Zones, and Why They Are Hard

01Why Noon Moved
02The Railways Force the Issue
03Drawing the First Lines
04One Meridian, Twenty-Five Votes
05Summer Time, and Who Wanted It
06The Database Nobody Funds

Rename, reorder, insert, remove. Editing the outline calls nothing and costs nothing.

Chapter one ≈ $0.25 Write it

Why Noon Moved

Chapter one

Why Noon Moved

A church clock in Bristol ran about ten minutes behind one in London, and both of them were right. Right meant “agrees with the sun outside”.

Every town kept its own noon, because noon was a thing you could see. The sun stood at its highest and the clock said twelve, and if your clock disagreed it was your clock that was wrong.

This was not a problem for anyone who could not travel faster than a horse. It became one the week the railways opened.

A timetable is a promise about a moment, and a promise about a moment needs two people to agree on which

Writing — you can leave the app

It stops before any chapter has text, so you see the shape of the book — and what it costs — before a word is paid for.

The problem

Nobody has written the book you need.

A model will draft you a chapter about anything today. Turning that into a book you can sit down and read — on the right topic, at the right depth, in something that behaves like a reader — is the part nobody has done.

What it takes now

Search for a book on exactly your topic.
Settle for one that is half about it.
Or ask a chatbot, one chapter at a time.
Convert the answers to EPUB by hand.
Get the file onto the phone.
Read it in a separate e-reader.
Hit a dense passage — copy, switch apps, ask.

Every step costs a file conversion or an app switch, so you stop asking for the book you wanted and read the one that exists.

What it takes here

Say what you want a book about.
Answer a few questions.
Read.
Hold a passage and say what is wrong with it.

One to three are the book, and they are most of the app. Four is what you do to it without ever leaving the page.

The MetaBook reader: chapter one of a book set in a book typeface, with its version, history and answers under the title. — The reader, as it ships. A frame from the app, not a mock-up.

The same reader in the app's night theme: the chapter in pale type on near-black, its version, history and answers under the title. — The reader, as it ships. A frame from the app, not a mock-up.

Before you pay

Read a whole book in it first.

Every install comes with a book already on the shelf, so there is something to read before you have a key. Here is a whole one, laid out the way the app lays it out: three chapters, a formula, a table and a picture.

Read the sample book

It is the shape every book takes — an outline you accepted, chapters written one at a time, and any paragraph rewritable in place. The ones you make are written by the model, to your brief.

While reading

Hold a passage. Say what is wrong with it.

No brief survives contact with a paragraph that is too dense. So the second half of the app is one gesture: touch and hold any paragraph, and a toolbar appears — Rewrite, Ask, Edit and copy. Every paid action states its price on the control before you press it.

Chapter one

Why Noon Moved

A church clock in Bristol ran about ten minutes behind one in London, and both were right. Right meant “agrees with the sun outside”.

The sun is not a good clock either

Even the sun does not keep to its own schedule. The earth’s orbit is an ellipse and its axis is tilted, so apparent solar time — noon as the sun actually calls it — runs ahead of the mean solar time a clock keeps for part of the year and behind it for the rest.

The sun is not a steady clock either. The earth travels round the sun in an oval, and it leans as it goes, so the noon a sundial shows runs ahead of the noon a clock keeps for part of the year, and falls behind it for the rest of it.

The gap has a name, the equation of time, and it is worth up to about sixteen minutes.

What broke it

Sixteen minutes is nothing to anyone standing in a field. It is a great deal to a railway. A timetable is a promise about a moment, and a promise about a moment needs two people to agree on which moment is meant.

The passage and its two neighbours are what the model is sent. Not the chapter.

01

Simplify

Plainer words, in place. The cheapest and fastest call the app makes, because you run it while reading.
02

Expand

The same ground at greater length — for the paragraph that went past something you wanted more of.
03

Example

A short worked case, written into the book where the abstraction was.
04

Illustrate

A picture of what the passage describes, placed directly under it and kept in the book. Around 8¢.
05

Or say it in your own words

Say which years. Give this its own paragraph. This contradicts chapter two. One instruction per call, and only the passage changes.

Ask answers a question without touching the book and keeps the answer on the passage. Edit is by hand and costs nothing. Undo restores the previous text as a new version, so nothing is ever lost. What makes rewriting in place safe.

The reader in the brief does not have to be you. Answer the interview about somebody else — the new hire, a student, a parent and their new phone — read it through, and export them the EPUB. Writing for somebody else.

Setup

Three steps. About five minutes.

MetaBook has no server, so it cannot pay for your generation. You bring an OpenRouter account, and the app walks you into it.

1

Buy it on Google Play

$5, once. There is no subscription and nothing else to buy from us, ever.
2

Connect OpenRouter

The key screen asks one question: do you already have an OpenRouter key? Paste it if you do. If not, tap Connect, approve it in the browser, and the app is given a key of its own with its own limit. OpenRouter is one account in front of hundreds of models and it is the only provider the app talks to — a key from OpenAI or Anthropic will not work directly, but their models are on the menu.
3

Put a few dollars on it

Five dollars of credit is about twenty eight-chapter books on the default model. The app shows an estimate before every call, keeps a ledger on the phone, and stops at a daily cap you can move.

Without a key you can still open the app and read the sample book. Nothing new is written until a key is there.

Money & privacy

You are spending your own money, so the app never hides it.

Every call is billed to the provider account your key belongs to, at the provider's price, with nothing added by us. There is no server of ours in the path and no analytics anywhere in the app.

An estimate before, a figure after. Anything that spends says what it will cost before it runs, and what it actually cost when it is done. Estimates are quoted high.
A daily cap and a per-book budget, on by default. They refuse rather than warn. Raising one is a decision you make in Settings, deliberately, not mid-chapter.
Every call writes a row. The ledger is on your device and it is yours to read: what the call was for, which model, what it cost.
Your key lives in the phone's secure storage. Keychain on iOS, Keystore on Android. It never reaches a log, an export or a backup.
Your text goes to your provider, and nowhere else. What you type and what your books hold leave the device only inside a model call addressed to OpenRouter.
The library is one file on your phone. Back it up whole, restore it on another phone, or delete all of it, key included, in one action that says exactly what it removes.

The full accounting · Privacy policy

The rewrite sheet in MetaBook: Simplify, Expand, Example and Illustrate, each showing an estimated price before it is pressed, and a field for saying what is wrong in your own words. — The rewrite sheet, with the prices on the controls. A frame from the app.

The same rewrite sheet in the app's night theme: Simplify, Expand, Example and Illustrate on dark cards, each with its estimated price, and a field for saying what is wrong in your own words. — The rewrite sheet, with the prices on the controls. A frame from the app.

Before you buy it

What it does not do.

It needs an API key. MetaBook is $5 once and has no server, which means it cannot pay for your generation. You bring an OpenRouter account — connecting one takes a couple of taps — and the bill for model calls is yours. Without a key you can look around and read the sample book, but nothing new is written.
The chapters are written by a language model, and checked by nobody. A model states wrong things as confidently as right ones. A book here is a good starting point and a bad citation.
No fiction. This is for non-fiction and for learning. Novels are a different job and it does not do that job.
Phones only. Android now, iPhone soon. There is no web version and no desktop one.
No accounts, so no sync. Your library lives on one device. Moving it to another is a backup file you carry across yourself.
A book you write for somebody else leaves as a file. Export it and they read it in whatever opens an EPUB. There is no way to hand somebody a book that is still live — the reading actions need the app, a key of their own, and the book on the device it was made on.

Ask for the book you wanted.
Then change it as you read.

$5 once on Google Play. What you spend after that is what your provider charges, and the app tells you before you spend it.

Get it onGoogle Play

iPhone: coming soon. Leave an email and you get one message, the day it is on the App Store.

You are on the list. One email when it ships, then the address is deleted.

That did not go through — check the address and try again.

A book about exactly your thing, at exactly your level.

Simplify

Expand

Example

Illustrate

Or say it in your own words

Buy it on Google Play

Connect OpenRouter

Put a few dollars on it

Ask for the book you wanted.Then change it as you read.

Ask for the book you wanted.
Then change it as you read.