# NumberBook vs PDF Reader Light & Simple

The clearest difference is review sentiment: PDF Reader Light & Simple at 100% against NumberBook's 20%. PDF Reader Light & Simple also leads on in-app purchases (none vs 2). NumberBook's advantage is update cadence (every 2 months vs every 19 months) and iOS requirement (12.1 vs 15.6). On price, ads and device support there is nothing between them.

Both are free to download. NumberBook sells 2 in-app purchases, starting at $3.99 per month. PDF Reader Light & Simple asks for nothing beyond the download.

NumberBook ships an update every 2 months, PDF Reader Light & Simple every 19 months. Both last shipped on November 3, 2026.

## The numbers

| Metric | NumberBook | PDF Reader Light & Simple |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.5 (6 ratings)](https://appshunter.io/ios/app/numberbook-who-is-calling/id1562671732/reviews)** | — |
| Number of ratings | **6** | — |
| Positive reviews | 20.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 19 months |
| Monetization | Subscription | **Free** |
| Size | 36 MB | 12 MB |
| Requires iOS | **12.1** | 15.6 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Numbo s.r.o.](https://appshunter.io/developer/1548761994) | [Adaptive Channel](https://appshunter.io/developer/1200824197) |

## What reviewers say

### NumberBook

[App page](https://appshunter.io/ios/app/numberbook-who-is-calling/id1562671732)

Instantly identify unknown callers and protect yourself from scams with a vast global database. Perform reverse phone lookups to discover caller identity, location, and user-reported categories like spam or trustworthy. Block unwanted numbers with a personalized blacklist.

**Highlights:** Unknown call identification, Reverse phone lookup, Spam and scam protection, Company and business identification, Customizable blacklist, User-reported number categories

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium - one month | $3.99 | per month |
| Premium - one year | $14.99 | per year |


### PDF Reader Light & Simple

[App page](https://appshunter.io/ios/app/pdf-reader-light-and-simple/id1563235539)

Easily read PDF files with this lightweight and fast application. It offers optimized performance for iPhones and iPads, along with bookmark management and quick navigation features. Enjoy a seamless reading experience without any advertisements.

**Highlights:** Lightweight and fast performance, Optimized for iPhone and iPad, Bookmark management, Fast and easy navigation, Ad-free experience

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

**In-app purchases:** none


## Frequently asked questions

### Is NumberBook free?

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

### Is PDF Reader Light & Simple free?

PDF Reader Light & Simple is free to download, with no in-app purchases.

### Do NumberBook or PDF Reader Light & Simple have ads?

Neither NumberBook nor PDF Reader Light & Simple shows ads.

### Which is updated more often, NumberBook or PDF Reader Light & Simple?

NumberBook ships an update every 2 months, and PDF Reader Light & Simple every 19 months. Most recently, NumberBook was updated on November 3, 2026 and PDF Reader Light & Simple on November 3, 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.*