Comparison

Natural Syntax vs Lectio Markdown / PDF Reader

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Natural Syntax

This app enhances reading comprehension by subtly styling text to highlight parts of speech, similar to syntax highlighting in programming. It offers a native ePub reader with full text search and a discovery service for public domain books. Users can customize styling and themes for an improved reading experience.

Highlights
  • Syntax highlighting for parts of speech
  • Native paginated ePub display
  • Full text search
  • Public domain book discovery
  • Customizable colors and styles
  • Multiple themes (Dark, Light, White)
Features
Read full description

As programmers read source code we passively absorb some of the meaning via syntax highlighting for the language. NaturalSyntax aims to do the same thing with natural human language, this will improve reading comprehension and understanding by passively absorbing the parts of speech via subtle styling of the text. Features: • Fully native paginated display of syntax highlighted parts of speech for ePub files • Full text book search • ePub parsed on demand for improved experience • Includes discovery service to download thousands of public domain books • Allows customization of colors and styles for each part of speech • Includes Dark, Light and White themes with different default colors • Allows you to turn on or off highlighting of each part of speech • Synchronizes preferences between all your devices • Uses system interface for interacting with your files • Does not collect or store any personal information Limitations: • Can only process English ePub files • Can only search for public domain books when signed into iCloud

About

Lectio Markdown / PDF Reader

Features
Read full description

A bookshelf for your PDFs and Markdown files, on iPhone and iPad. Bring in files from the cloud or the Files app, turn their pages in two-page spreads, and write on them with Apple Pencil. Made for you if • You want to read scanned books and comics in spreads, the way you read them on paper • You read papers and documents and want to write notes on them with Apple Pencil • You keep notes, AI chat logs or READMEs in Markdown and want to read them calmly, page by page • Your PDFs are scattered across cloud services and you want them on one shelf Collect: PDFs and Markdown on one shelf From "Add Books", bring in files from any place that appears in the Files app, such as iCloud Drive, Google Drive, OneDrive and Dropbox. You can also open Lectio from the share sheet in another app, or drag and drop files onto the shelf. A Markdown (.md) file becomes an A4 PDF with its headings, lists, tables and code laid out, and takes its place on the shelf. The same file is never added twice, and password-protected PDFs can be added too. Books are kept on your device, so you can read them without a connection. Lectio only reads your cloud files and never changes or deletes them. Read: turn pages like a book Each book remembers its layout (two-page, single page or vertical scroll) and its left or right binding. Right-bound books lay out their spreads from right to left, so comics and vertical text read in their natural direction. Swipe or press the arrow keys to turn the page, and tap the page to hide the buttons. Lectio remembers where you stopped, so the next time you open a book you carry on from there. Switch the page color to night or sepia, adjust the brightness, and keep the screen on while you read. Write: Apple Pencil and four highlight colors Turn on Handwriting in the toolbar and a tool palette appears. Write directly on the page with Apple Pencil or your finger, choose pens, colors and the eraser, and your writing stays with each page. Highlight text in yellow, green, pink or blue, and find your highlights again under Highlights in the sidebar. Press and hold text to copy it, look it up or search the book for it, and tap links on the page. Find: contents, thumbnails and text search Jump to a chapter from the table of contents, or to any page from the thumbnail grid or by its page number. Search the text of a book and each match is highlighted in yellow. Books made from Markdown are searchable too. In the library, find books by name. Organize: favorites, bookmarks and collections Each cover shows how far you have read: New, a percentage, or Finished, and you can sort by Recently Read. See your favorite books, bookmarked pages and highlights in lists. A bookmark keeps the opening words of its page, so you know where you left it. Sort books into collections and arrange them in any order you like. Rename books, or select several to share them, add them to a collection or delete them in one go. Deleted books stay in Recently Deleted for 30 days, where you can bring them back. Widget, Spotlight and Handoff The Home Screen widget shows the books you read recently, and tapping one opens it where you left off. Search for books in Spotlight by name or by words in the text. With Handoff, pass the book and page you are reading to another iPhone or iPad that has the same PDF. iPhone, iPad and iPhone Duo Lectio supports iPhone Duo. Read on the outer display when it is closed, and in spreads on the large inner display when you open it. The buttons sit in the vertical bar along the edge, out of the way of the page. Keyboard, remotes and VoiceOver Press ⌘O to add books, ⌘F to search, ⌘B to bookmark and ⌘W to close. Pages turn with the arrow keys, so a Bluetooth keyboard or a page-turner remote that sends arrow keys works too. VoiceOver and Dark Mode are supported. You can also share and print your books. Start by tapping + in the library and add your first book.

Screenshots

Natural Syntax4 screens
Lectio Markdown / PDF Reader4 screens

Verdict

The call

The clearest difference is in-app purchases: Lectio Markdown / PDF Reader at none against Natural Syntax's 1. Lectio Markdown / PDF Reader also leads on update cadence (every 2 days vs every 12 months). Natural Syntax's advantage is iOS requirement (12.0 vs 27.0). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Natural Syntax sells 1 one-off in-app purchase. Lectio Markdown / PDF Reader asks for nothing beyond the download.

UpkeepUpdate frequency

Natural Syntax ships an update every 12 months, Lectio Markdown / PDF Reader every 2 days. The most recent releases landed on October 12, 2026 and October 24, 2026 respectively.

Scorecard3 real differences · 7 level
Natural Syntax versus Lectio Markdown / PDF Reader: the parameters behind the verdict, then further details
ParameterNatural SyntaxLectio Markdown / PDF Reader
PriceFreeFree
Rating4.0 (2 ratings) — better—
Positive reviews66.7% of reviews—
Number of ratings2 — better—
Update frequencyEvery 12 monthsEvery 2 days — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS12.0 — better27.0
Further details — not scored
Size11 MB20 MB
Age rating12+4+
DeveloperJeremy Buchmancaps-rock

In-app purchases

1 purchases

Natural Syntax

One-time1
  • Color Customization$0.99
None

Lectio Markdown / PDF Reader

No in-app purchases

Questions

Is Natural Syntax free?
Natural Syntax is free to download, with in-app purchases available.
Is Lectio Markdown / PDF Reader free?
Lectio Markdown / PDF Reader is free to download, with no in-app purchases.
Do Natural Syntax or Lectio Markdown / PDF Reader have ads?
Neither Natural Syntax nor Lectio Markdown / PDF Reader shows ads.
Which is updated more often, Natural Syntax or Lectio Markdown / PDF Reader?
Natural Syntax ships an update every 12 months, and Lectio Markdown / PDF Reader every 2 days. Most recently, Natural Syntax was updated on October 12, 2026 and Lectio Markdown / PDF Reader on October 24, 2026.

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