# ZB Study vs Underline

The clearest difference is in-app purchases: ZB Study at none against Underline's 3. ZB Study also leads on ads (none vs shown). On price, update cadence, device support and iOS requirement there is nothing between them.

Both are free to download. Underline sells 3 in-app purchases, starting at $0.99 per month. ZB Study asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 2 days. Both last shipped on October 24, 2026.

## The numbers

| Metric | ZB Study | Underline |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/zb-study/id6741779441/reviews)** | — |
| Number of ratings | **2** | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 2 days | Every 2 days |
| Monetization | Free | — |
| Size | 56 MB | 48 MB |
| Requires iOS | **15.1** | 15.5 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [East Watch Services](https://appshunter.io/developer/366652962) | [Zeynal Abidin UNLU](https://appshunter.io/developer/6811378018) |

## What reviewers say

### ZB Study

[App page](https://appshunter.io/ios/app/zb-study/id6741779441)

Access and study religious texts, including the Bible and Book of Mormon, directly on your mobile device. Search scriptures, explore doctrines, and deepen your understanding of sacred writings anytime, anywhere.

**Highlights:** Search scriptures, Study religious texts, Access Bible, Access Book of Mormon, Access Doctrine & Covenants, On-the-go study

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

**In-app purchases:** none


### Underline

[App page](https://appshunter.io/ios/app/underline-book-quotes-and-notes/id6821564891)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Underline Pro Monthly | $0.99 | per month |
| Underline Pro Yearly | $4.99 | per year |
| Underline Pro Lifetime | $9.99 | one-time |


## Frequently asked questions

### Is ZB Study free?

ZB Study is free to download, with no in-app purchases.

### Is Underline free?

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

### Do ZB Study or Underline have ads?

Underline shows ads; ZB Study does not.

### Which is updated more often, ZB Study or Underline?

ZB Study ships an update every 2 days, and Underline every 2 days. Most recently, ZB Study was updated on October 24, 2026 and Underline on October 24, 2026.

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