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Features

Everything you need to read well.

Adaptive typography, real structure, annotations that keep their place, and a library that travels with you.

Features

Everything a reader needs. Nothing between you and the words.

Reading

  • Adaptive Typography

    Literata, Gelasio, Inter, Atkinson Hyperlegible or OpenDyslexic, at the size you choose.

  • Dynamic Pagination

    Page count automatically adjusts as your layout changes — your place never moves.

  • Beautiful Themes

    Light, Sepia, Dark and Black (for OLED screens), each tuned for comfortable contrast.

  • Custom Reading Layout

    Control margins, line spacing, paragraph spacing and alignment.

  • Paged or Scrolling

    Turn pages with Slide, Cover, Turn or Fade effects — or read in one continuous scroll.

Navigation

  • Table of Contents

    Jump directly between chapters and sections of the rebuilt book.

  • Search

    Search the complete book and land on the exact passage — even offline for downloaded books.

  • Reading Progress

    Continue exactly where you stopped — even after changing fonts or devices.

  • Library & Collections

    Currently reading, want to read, favourites, categories and your own collections.

Annotation

  • Bookmarks

    Save important reading positions and return to them in a tap.

  • Highlights

    Highlight passages in six colours, and recolour them any time.

  • Notes

    Attach your own notes to any passage.

  • Define, Copy & Share

    Look up a word, copy a quote or share a passage straight from a selection.

Everywhere

  • Offline Reading

    Download books and read without an internet connection.

  • Cross-Device Sync

    Progress, annotations and preferences follow you across devices.

  • Reading Statistics

    Streaks, reading time, pages and speed — understand your reading habits.

Dynamic pagination

Pages That Fit Your Reading.

A traditional PDF has a fixed number of pages. Reflow creates its own reading pages by measuring how your book is actually laid out on your screen.

Reading pages are calculated from

  • Font
  • Font size
  • Screen dimensions
  • Margins
  • Line spacing
  • Paragraph spacing
  • Images
  • Layout

Chapters you have opened get exact page numbers straight away; the rest start as a calibrated estimate (shown as ~281) and are refined in the background.

Reading pages are a way of presenting the book on your screen. Your original PDF — and its page numbers — are never modified.

16px280reading pages
20px318reading pages
24px367reading pages

Bookmarks, highlights & notes

Mark what matters. It stays where you left it.

Annotations are attached to the underlying text, not to a page number. Change the font, the size or the device — your highlights, notes and bookmarks remain on the right words.

Next: Highlight

Reflow book details screen for Greedy Primates by Prabhasudhan: the cover, 11% complete with 1 hour 4 minutes left, a Continue Reading button, 30 chapters, 85 PDF pages, 1 hour 12 minutes to read, and a short description.

Offline reading

Read anywhere. Even at 35,000 feet.

Once a book has been processed, download it to your device from the book page or the reader menu. No continuous connection required.
  1. 01

    Download a processed book

    Keep any book from your library on your device.

  2. 02

    Read anywhere

    Highlights, notes, bookmarks and progress all work offline.

  3. 03

    Sync when you’re back

    Changes made offline are queued and synchronise automatically when you reconnect.

Reading statistics

Notice your reading life.

Gentle insights into how you read — streaks, time, pages and pace. Never leaderboards, never pressure.
Day streak
23days
Books completed
14
Reading time
62h
Pages read
4,180
Average speed
241wpm
Average session
27min
Minutes read this week285 min total
Minutes read per day this week (sample data)
DayMinutes
Mon34
Tue21
Wed48
Thu15
Fri39
Sat72
Sun56

Pages are counted as 300 words each, so they mean the same in every book and at every font size. Sample data for illustration. View daily, weekly or monthly in the app.

Intelligent assistance

Your Books Can Become More Interactive.

AI is an optional companion to reading, never a requirement. The book you read is always the author’s text — assistance appears only when you ask for it.

AI never rewrites your book. It answers questions about it.

Reflow Ask the book screen with the request "Summarize this chapter" and a summary of the chapter below it, with numbered citations to the passages it draws on.

Available now

  • Ask the Book

    Available

    Ask questions and get answers grounded in the book, with citations that open the passage they came from.

  • Explain a Passage

    Available

    Select a difficult paragraph and tap Explain for a plain-language explanation.

  • Summarize a Chapter

    Available

    Recap a chapter before you continue, or after a long break.

  • Explain Difficult Concepts

    Available

    Ask about an idea or term and get it unpacked in the context of the book.

  • Dictionary

    Available

    Select a word and tap Define to look it up without leaving the page.

Coming soon

  • Translation

    Coming soon

    Translate a word, sentence or passage without leaving the page.

  • AI Reading Assistant

    Coming soon

    A study companion for notes, review and comprehension.

Privacy & security

Your library is yours.

We built Reflow on a simple principle: your books and your reading life belong to you. Here is what that means in practice.
  • Secure account authentication

    Passwords are stored only as strong one-way hashes, and sign-in sessions use short-lived, rotating tokens.

  • Encrypted connections

    The app talks to our servers over HTTPS. Sign-in tokens are kept in your device’s secure keychain.

  • Private cloud storage

    Books are kept in private storage tied to your account; images are delivered through short-lived signed links.

  • A library you control

    Your books are private to your account — they are never shared with other readers.

  • Delete any time

    Delete a book along with its highlights, notes and bookmarks — or your whole account — right in the app.

  • Privacy-focused design

    We collect what the service needs, and explain it plainly in our Privacy Policy.

Read the details in our Privacy Policy and how to delete your data.

Supported devices

Designed for the screen you’re holding.

The reading layout is calculated for each device, so the same book feels at home on a phone or a tablet.
  • iPhone
  • iPad
  • Android phones
  • Android tablets

Download

Bring Your Books With You.

Reflow — your PDFs, rebuilt for reading — on iPhone, iPad and Android.

Coming soonApp StoreComing soonGoogle Play

Coming soon to iOS and Android

We’re putting the finishing touches on the store releases. Leave us a note and we’ll let you know when they’re available.

Contact us