read your book in Reels.
Finally finish the classics.
Thousands of public-domain classics, one paragraph per swipe, with an AI that reads with you, not for you.
The library and both reading modes are free. IO+ is $2.99 a month for unlimited companions.
REELS
One paragraph fills the screen.
Swipe up and the next paragraph takes the screen. One paragraph, your full attention, then the next.
SENTENCE CARDS
Or one sentence at a time.
Tap the mode toggle and the same paragraph splits into cards. Slow is a feature.
READING COMPANIONS
A companion for the page you are on.
Tap AI and a reading companion opens over the passage on screen. It works on that passage, not on a summary of the book.
REELS
One paragraph fills the screen.
Swipe up and the next paragraph takes the screen. One paragraph, your full attention, then the next.
SENTENCE CARDS
Or one sentence at a time.
Tap the mode toggle and the same paragraph splits into cards. Slow is a feature.
READING COMPANIONS
A companion for the page you are on.
Tap AI and a reading companion opens over the passage on screen. It works on that passage, not on a summary of the book.
TWELVE READING COMPANIONS
Twelve reading companions, one for every page.
Historian, Psychologist, Vocab Coach and nine more read alongside you. Tap a card to read the real response IO reader gave.
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Interpreter
Rewrites the passage to match your reading profile and style preference.
But the effect of her being on those around her was incalculably diffusive: for the growing good of the world is partly dependent on unhistoric acts; and that things are not so ill with you and me as they might have been, is half owing to the number who lived faithfully a hidden life, and rest in unvisited tombs.
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Critical Thinker
Surfaces hidden assumptions and second-order implications in the text.
Nothing remains then but the recollection of a pleasure, or the luxury of a regret. The only way to get rid of a temptation is to yield to it. Resist it, and your soul grows sick with longing for the things it has forbidden to itself, with desire for what its monstrous laws have made monstrous and unlawful.
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Translator
Translates the passage into your chosen language with native-speaker naturalness.
“Live, then, and be happy, beloved children of my heart, and never forget that until the day when God shall deign to reveal the future to man, all human wisdom is summed up in these two words,—‘Wait and hope.’
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Historian
Contextualizes the passage in its historical and cultural moment.
On an exceptionally hot evening early in July a young man came out of the garret in which he lodged in S. Place and walked slowly, as though in hesitation, towards K. bridge.
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Philosopher
Surfaces the philosophical question or tradition embedded in the text.
Begin the morning by saying to thyself, I shall meet with the busybody, the ungrateful, arrogant, deceitful, envious, unsocial. All these things happen to them by reason of their ignorance of what is good and evil. But I who have seen the nature of the good that it is beautiful, and of the bad that it is ugly, and the nature of him who does wrong, that it is akin to me, not only of the same blood or seed, but that it participates in the same intelligence and the same portion of the divinity, I can neither be injured by any of them, for no one can fix on me what is ugly, nor can I be angry with my kinsman, nor hate him. For we are made for cooperation, like feet, like hands, like eyelids, like the rows of the upper and lower teeth. To act against one another then is contrary to nature; and it is acting against one another to be vexed and to turn away.
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Psychologist
Analyzes character motivations, emotional patterns, and psychological dynamics.
“You are in the wrong,” replied the fiend; “and instead of threatening, I am content to reason with you. I am malicious because I am miserable. Am I not shunned and hated by all mankind? You, my creator, would tear me to pieces and triumph; remember that, and tell me why I should pity man more than he pities me?
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Rhetorician
Dissects the author's craft — word choice, rhythm, and rhetorical devices.
Happy families are all alike; every unhappy family is unhappy in its own way.
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Questioner
Asks escalating questions to challenge your assumptions about the passage.
Why, then ’tis none to you; for there is nothing either good or bad but thinking makes it so. To me it is a prison.
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Vocab Coach
Picks notable words, defines them in context, and gives memory hooks.
Call me Ishmael. Some years ago—never mind how long precisely—having little or no money in my purse, and nothing particular to interest me on shore, I thought I would sail about a little and see the watery part of the world. It is a way I have of driving off the spleen and regulating the circulation. Whenever I find myself growing grim about the mouth; whenever it is a damp, drizzly November in my soul; whenever I find myself involuntarily pausing before coffin warehouses, and bringing up the rear of every funeral I meet; and especially whenever my hypos get such an upper hand of me, that it requires a strong moral principle to prevent me from deliberately stepping into the street, and methodically knocking people’s hats off—then, I account it high time to get to sea as soon as I can. This is my substitute for pistol and ball. With a philosophical flourish Cato throws himself upon his sword; I quietly take to the ship. There is nothing surprising in this. If they but knew it, almost all men in their degree, some time or other, cherish very nearly the same feelings towards the ocean with me.
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Quiz Master
Generates comprehension, inference, and open-ended questions to test understanding.
It is a truth universally acknowledged, that a single man in possession of a good fortune must be in want of a wife.
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Note-Taker
Produces a structured study note: Key Idea, Detail, Key Quote, Why It Matters.
I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived. I did not wish to live what was not life, living is so dear; nor did I wish to practise resignation, unless it was quite necessary. I wanted to live deep and suck out all the marrow of life, to live so sturdily and Spartan-like as to put to rout all that was not life, to cut a broad swath and shave close, to drive life into a corner, and reduce it to its lowest terms, and, if it proved to be mean, why then to get the whole and genuine meanness of it, and publish its meanness to the world; or if it were sublime, to know it by experience, and be able to give a true account of it in my next excursion.
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Futurist
Connects the passage's core idea to a present-day or future implication.
But to me the future is still black and blank—is a vast ignorance, lit at a few casual places by the memory of his story. And I have by me, for my comfort, two strange white flowers—shrivelled now, and brown and flat and brittle—to witness that even when mind and strength had gone, gratitude and a mutual tenderness still lived on in the heart of man.
KEEPSAKE BOX
The lines that stopped you, kept.
Like a sentence and it goes to your Keepsake Box, under its chapter, with your note attached. A shelf of your own underlinings, not the whole book again.
THE LIBRARY
Thousands of classics, free and unabridged.
Search any author. Standard Ebooks editions first. Bring your own EPUB and web articles; no lock-in.
Cover credits
- White Nights: Vincent van Gogh, Starry Night Over the Rhône (1888), public domain — substitute art, not the edition cover
- Notes from Underground: Standard Ebooks CC0 cover, fyodor-dostoevsky/notes-from-underground/constance-garnett
- Crime and Punishment: Standard Ebooks CC0 cover, fyodor-dostoevsky/crime-and-punishment/constance-garnett
- Meditations: Standard Ebooks CC0 cover, marcus-aurelius/meditations/george-long
- Pride and Prejudice: Standard Ebooks CC0 cover, jane-austen/pride-and-prejudice
- Frankenstein: Standard Ebooks CC0 cover, mary-shelley/frankenstein
- Moby Dick: Standard Ebooks CC0 cover, herman-melville/moby-dick
- Anna Karenina: Standard Ebooks CC0 cover, leo-tolstoy/anna-karenina/constance-garnett
- The Picture of Dorian Gray: Standard Ebooks CC0 cover, oscar-wilde/the-picture-of-dorian-gray
- Walden: Standard Ebooks CC0 cover, henry-david-thoreau/walden
- The Great Gatsby: Standard Ebooks CC0 cover, f-scott-fitzgerald/the-great-gatsby
- Dracula: Standard Ebooks CC0 cover, bram-stoker/dracula
WHAT TO READ NEXT
Never stuck for the next book.
Home opens on For You, a shelf built from how you read, for IO+ members, and on curated lists anyone can browse. Search carries the Issue, an editorial selection refreshed regularly, so there is always something chosen to open next.
EXACTLY WHAT IT LOOKS LIKE
Captured from the shipped app.
iPhone and Android.
THE SAME PAGE, ELSEWHERE
The same page, in IO reader and elsewhere.
| IO reader | Kindle | Apple Books | Serial Reader | Blinkist | |
|---|---|---|---|---|---|
| One paragraph per screen (Reels) | Yes | No | No | No | No |
| One sentence per screen (cards) | Yes | No | No | No | No |
| AI that works on the passage, never summarizes | 12 companions | Ask this Book (Q&A) | No | No | Summaries only |
| Public-domain classics free | Thousands | Many, in the store | Some | 800+ | No (summaries) |
| Import your own EPUB | Yes | Send-to-Kindle | Yes | No | No |
PRICE
Free forever. IO+ when you want more.
Free to read. Pay only for more companions.
Free
$0
- The full library, both reading modes
- Themes, notes, and streaks
- 100 Advanced-model reading-companion responses to start, then five a month
IO+
$2.99/mo
or $24.99/yr
- Unlimited responses from all twelve reading companions
- AI search across the library
- AI For You
- Cross-device sync
Frequently asked questions
Does the AI summarize the book?
No. Every reading companion is instructed not to summarize; each one works on the passage in front of you — context, craft, motive, vocabulary, questions. The Questioner is the only one that turns toward you, and it asks rather than tells.
Is IO reader free?
Yes. The full library, both reading modes, themes, notes and streaks are free. Free includes 100 Advanced-model reading-companion responses to start, then five a month. IO+ is $2.99 a month or $24.99 a year for unlimited reading companions, AI search, AI For You and cross-device sync.
Can I read my own EPUB files?
Yes. Import any DRM-free EPUB or save a web article; they read in Reels and cards like everything else.
Is it on Android?
Yes, on Google Play (Android 10 and later) since September 2026, alongside iPhone.
Which translations are used?
Public-domain editions, named on every book page — Constance Garnett for Dostoevsky and Tolstoy, George Long for Marcus Aurelius.
What does "Reels" mean for a book?
One paragraph fills the screen; swipe up for the next. Tap the toggle for one sentence at a time. It is the book, unabridged, in the gesture you already use.
A NOTE ON INTENT
Built for people who reread.
IO reader is built on an unfashionable idea: that reading should change you, not just pass through you. The evidence we gathered says depth compounds over a reading life, and that the dose that matters is the habit. So every part of the app protects the habit: the whole book, one paragraph at a time; companions that work on the passage instead of summarizing it; a box for the lines that kept you.