Resonance turns any PDF or ebook into a reading room — narration that follows every sentence, a margin for what you notice, and a reader that learns what you read toward.
Books, articles, the PDF a friend sent — all in one quiet library, with a card that picks up exactly where you left off. No feed, no clutter; just what you're reading next.

Drop in a PDF or ebook and Resonance begins reading aloud almost immediately — a live highlight follows each sentence, and you can tap any word to jump there.
Swipe to highlight in five colors, with an Apple Pencil or a fingertip. Linger on a passage and Resonance quietly offers to mark it for you — never silently, always your call.
Long-press any word and Resonance defines it in the context of what you're reading, grounded in real sources rather than a guess. Every lookup is saved, building a vocabulary from the books you actually read.
Rest your eyes and let the book come to you — Spotlight shows a single sentence, large and centered, in step with the voice. Reading as listening, without the page pulling at your attention.
Highlights, notes in your own hand, and voice notes all become cards you can read beside the text — the way you'd annotate a real book, then find it all again later.
When a thought is faster than typing, hold and speak — Resonance transcribes it into a note on the spot and keeps it with the passage, so nothing slips away mid-reading.
Ask what a passage means, who's being referenced, or for a quick summary — answered on your device by Apple Intelligence, so your reading never leaves your phone. AI that helps you read closely, not one that reads for you.
Every chapter, with where you are and what you've finished — tap to jump and both the text and the voice move there at once. Reading time and progress, always in view.
Resonance resurfaces the passages you marked, traces the themes that run across your books, and reflects a portrait of your reading — not streaks or scores, just what you've been thinking about.
Studio-quality narration runs entirely on-device — no quotas, no voice minutes, fully offline. Read in English, Korean, and more than thirty languages, in a voice that sounds human.
Honest pricing, no dark patterns. The reader is genuinely free; Premium is the part a committed reader needs second.
Yes — the full reader is free: all voices, highlights, notes, journal, lexicon, and on-device AI. Premium adds sync, larger imports, audiobook export, and deeper synthesis. New users get a 15-day trial of everything.
An iPhone or iPad on iOS/iPadOS 26.2 or later with Apple Intelligence — the reading and AI features rely on Apple's on-device models.
What you read, highlight, and note stays on your device. Only generic document text-processing is sent to a server, without your identity.