# Chaeksum - Calm Paper Reader — Ad-free reader: TXT, EPUB, PDF

> Ad-free reader: TXT, EPUB, PDF (iPhone/iPad app by JAEBAEK LEE.)

- Source: https://appshunter.io/ios/app/chaeksum-calm-paper-reader/id6818563802 (this page in markdown: same URL + `.md`)
- Developer: [JAEBAEK LEE](https://appshunter.io/developer/6818554389)
- Category: Books, Productivity
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.4 · 38 MB
- Languages: American English, Japanese, Korean
- Released: 2026-10-08
- Data updated: 2026-10-17

## What is Chaeksum?

Chaeksum is a reading app with no ads. The name is Korean for "the breath of a book".
No banners, no pop-ups, no video ads. When you read, there is only text.
Made for people who loved e-ink readers and now read on their phone.

Easy on the eyes
• The page is never brighter than the room around you, with less flicker in the dark
• Warm grey paper without blue glare, warmer after sunset
• Black & white mode for this app only
• Turn page by page with your choice of effect, or scroll straight down (trial)
• The screen stays on while you read, and brightness is right there in the reader

Any file, fast
• TXT, EPUB and PDF — password-protected PDFs too
• Import a ZIP of books in one go
• EPUBs keep their own table of contents and footnotes
• Even books thousands of pages long open in about a second
• Link your Downloads folder once and new books appear right away
• Find, sort and rename books in your library
• On iPad in landscape, two pages side by side like a book — PDFs too, with contents and search

While you read
• Highlights, notes, bookmarks and full-text search; step through matches with ‹ ›
• Long-press to select, drag the handles, and carry on onto the next page
• Share a passage as a paper card image
• Dictionary and translation
• Read aloud with natural voices and a sleep timer (10 free minutes a day)
• Turn pages with a keyboard or a Bluetooth page turner
• Choose what the page header and footer show: title, chapter, pages left, time left, percent, progress bar
• Home Screen and Lock Screen widgets, plus today's reading time and your streak
• Lock the app with Face ID
• Export highlights and notes as text
• Literata, Charter and Korean book fonts — remembered separately for Korean and English books
• English, Korean and Japanese

Chaeksum Pro — buy once, keep forever (not a subscription)
• Fine typesetting: line and paragraph spacing, letter spacing, margins, weight, alignment
• Different fonts, spacing and margins per book; save your own presets
• Unlimited read-aloud
• Unlimited highlights and notes (free: unlimited in your first book, then 3 per book)
• Add your own fonts (.ttf, .otf)
• Every paper tone
• iPhone–iPad sync through your own iCloud: position, highlights, notes, bookmarks and book files (no sign-up)

Books bought from stores with DRM protection can't be opened. Chaeksum reads the TXT, EPUB and PDF files you own.

Tips
The app is made without ads. If you like it, you can buy the developer a coffee in Settings. Tips unlock nothing — they are just support.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Chaeksum Pro | $1.99 | one-time |
| Tip · A Coffee | $0.49 | one-time |
| Tip · Tea and Dessert | $1.99 | one-time |
| Tip · A Book | $6.99 | one-time |


## Is Chaeksum safe?

Not enough ratings yet to assess Chaeksum.

## Is Chaeksum legit?

Chaeksum - Calm Paper Reader appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for Chaeksum is 65 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 3 releases)

### 1.2.1 — 2026-10-15

A small update.
• When you finish one of your own books and head back to the library, you can rate Chaeksum if you like it (asked at most once per version, never for the sample)
• Clearer App Store page for people looking for a TXT or EPUB reader

### 1.2 — 2026-10-12

종이결이 ‘책숨’으로 이름을 바꿨어요. 책의 숨결처럼, 조용히 오래 읽는 앱이 되겠습니다. 읽던 책과 설정은 그대로예요.

더 편하고, 더 든든해졌습니다.
• 서재에서 책 찾기 · 정렬 · 이름 바꾸기
• 웹소설 ZIP을 그대로 가져오기 (안의 TXT · EPUB · PDF를 한 번에)
• TXT 목차를 더 잘 찾아요: 1화 · [12화] · 외전 · 번외 · 第1話
• EPUB은 책에 들어 있는 원래 목차를 그대로, 각주는 눌러서 바로
• 본문 검색 뒤 ‹ 다음 · 이전 › 으로 바로 이동, 멀리 이동한 뒤엔 ‘원래 쪽으로 돌아가기’
• 고른 문장을 종이 카드 이미지로 공유
• 오늘 읽은 시간과 이어서 읽은 날
• 읽어 주기 잠자기 타이머 (15 · 30 · 60분)
• Face ID로 앱 잠그기
• 읽는 동안 화면 켜 두기, 읽는 화면에서 밝기 조절, 쪽 번호로 이동
• 키보드 · 블루투스 페이지 리모컨으로 쪽 넘기기
• 암호 걸린 PDF 열기, 일본어 TXT(Shift-JIS) 열기
• 마지막 쪽을 넘기면 ‘다 읽었어요’
• 읽던 곳과 동기화를 더 정확하고 안전하게

### 1.1 — 2026-10-08

No release notes.

## More apps by JAEBAEK LEE

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- [잽잽원투: 라운드 타이머](https://appshunter.io/ios/app/id6818832694)
- [Meow Punch - Photo Cleaner](https://appshunter.io/ios/app/meow-punch-photo-cleaner/id6821323872)
- [MITO EDIT - Auto Video Editor](https://appshunter.io/ios/app/mito-edit-auto-video-editor/id6822125645)

All apps by JAEBAEK LEE: https://appshunter.io/developer/6818554389

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-17.*