# CalibReader vs Sumi Book

The clearest difference is chart position: CalibReader at #140 against Sumi Book's unranked. Sumi Book's advantage is iOS requirement (15.1 vs 26.2). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. CalibReader sells 1 one-off in-app purchase and Sumi Book sells 3 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

CalibReader ships an update every 3 days, Sumi Book every 5 days. The most recent releases landed on November 8, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | CalibReader | Sumi Book |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (6 ratings)](https://appshunter.io/ios/app/calibreader-epub-and-pdf-reader/id6777391511/reviews)** | — |
| Number of ratings | **6** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 3 days** | Every 5 days |
| Monetization | Free with in-app purchases | — |
| Best chart rank | **#140** | — |
| Size | 49 MB | 53 MB |
| Requires iOS | 26.2 | **15.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [Gram 1](https://appshunter.io/developer/1895687118) | [Oktay Demir](https://appshunter.io/developer/6777725671) |

## What reviewers say

### CalibReader

[App page](https://appshunter.io/ios/app/calibreader-epub-and-pdf-reader/id6777391511)

**Currently charting:** #140 Top Free · Book (US App Store)

This app offers a reading experience for EPUB and PDF files, featuring dual-page spreads and realistic page curls. It integrates with your existing calibre library and supports various cloud storage options. Enjoy a customizable reading environment and seamless syncing across devices.

**Highlights:** Dual-page spread and page curl effect, Calibre library integration, Cloud storage support (iCloud, Dropbox, OneDrive), Cross-device reading position sync, Customizable themes and fonts, Built-in dictionary, PDF reader with two-page spreads

**Features:** macOS Compatibility, Vision Pro support, iPhone Duo support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock All Books Forever | $9.99 | one-time |


### Sumi Book

[App page](https://appshunter.io/ios/app/sumi-book/id6777730252)

**Features:** macOS Compatibility, Vision Pro support, iPhone Duo support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| The Fine Press — Monthly | $3.99 | per month |
| The Fine Press — Annual | $24.99 | per year |
| The Fine Press — Lifetime | $49.99 | one-time |


## Frequently asked questions

### Is CalibReader free?

CalibReader is free to download, with in-app purchases available.

### Is Sumi Book free?

Sumi Book is free to download, with in-app purchases available.

### Do CalibReader or Sumi Book have ads?

Neither CalibReader nor Sumi Book shows ads.

### Which is updated more often, CalibReader or Sumi Book?

CalibReader ships an update every 3 days, and Sumi Book every 5 days. Most recently, CalibReader was updated on November 8, 2026 and Sumi Book on November 5, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*