# PDF Viewer by Nutrient vs Los OSOs

The clearest difference is price: PDF Viewer by Nutrient at Free against Los OSOs's $2.99. PDF Viewer by Nutrient also leads on ratings volume (9.1K vs 1) and device support (4 vs 2). Los OSOs's advantage is rating (5.0 vs 4.6) and review sentiment (100% vs 73%). On ads, in-app purchases and iOS requirement there is nothing between them.

PDF Viewer by Nutrient is free to download; Los OSOs costs $2.99 up front. PDF Viewer by Nutrient sells 2 in-app purchases, starting at $6.99 per 3 months and Los OSOs sells 2 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

Los OSOs holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: PDF Viewer by Nutrient has 9.1K ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 73% of PDF Viewer by Nutrient's written reviews are positive against 100% of Los OSOs's.

PDF Viewer by Nutrient ships an update monthly, Los OSOs every 6 days. The most recent releases landed on October 27, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | PDF Viewer by Nutrient | Los OSOs |
| --- | --- | --- |
| Price | **Free** | $2.99 |
| Rating | [4.6 (9.1K ratings)](https://appshunter.io/ios/app/pdf-viewer-by-nutrient/id1120099014/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/los-osos/id1672750235/reviews)** |
| Number of ratings | **9.1K** | 1 |
| Positive reviews | 73.3% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Monthly | **Every 6 days** |
| Monetization | **Freemium** | Paid |
| Size | 109 MB | 282 MB |
| Requires iOS | 17.0 | **16.2** |
| Devices | **iPhone, iPad, Mac, Vision Pro** | iPhone, Apple Watch |
| Age rating | 4+ | 17+ |
| Developer | [PSPDFKit GmbH](https://appshunter.io/developer/966931428) | [Nectelier Inc.](https://appshunter.io/developer/1481311829) |

## What reviewers say

### PDF Viewer by Nutrient

[App page](https://appshunter.io/ios/app/pdf-viewer-by-nutrient/id1120099014)

Easily view, search, and annotate PDF documents on your iPhone and iPad. Import files from cloud services, fill out forms, add signatures, and organize your documents. Advanced features like redaction and combining documents are available with a Pro subscription.

**Highlights:** View and search PDFs, Annotate with highlights and notes, Sign documents digitally, Fill out PDF forms, Organize and share documents, Import from cloud services

**Features:** Family Sharing, iMessage stickers

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PDF Viewer Pro 3 Months | $6.99 | per 3 months |
| PDF Viewer Pro Yearly | $19.99 | per year |

**What reviewers like**

- 🚀 Seamless integration with iCloud and Files app
- 👍 Intuitive annotation tools with Apple Pencil
- 🎨 Versatile highlighting and drawing options
- 💾 Saves annotations to original PDF files
- 🔍 Powerful search and navigation features

**What reviewers complain about**

- 🐛 Occasional crashes and performance issues
- 🤔 Confusing UI and steep learning curve
- 🔀 Difficulty managing and organizing PDF files
- 🔍 Inconsistent text selection and highlighting
- 🔒 Privacy concerns around data collection

**Reported bugs**

- Annotations randomly disappearing or not saving
- Incompatibility issues with certain PDF files
- Scrolling and panning problems on large PDFs
- Unexpected crashes after iOS updates

**Requested features**

- Add a rubber/eraser tool for annotations
- Implement a side-by-side PDF view mode
- Improve palm rejection and gesture support
- Allow customization of toolbar and shortcuts
- Provide better options for PDF file management


### Los OSOs

[App page](https://appshunter.io/ios/app/los-osos/id1672750235)

This app helps you understand and express your emotions through a unique, non-verbal system. Record and share your sentiment over time to improve self-awareness, leadership, and teamwork. Designed with an elegant and intuitive interface.

**Highlights:** Non-verbal sentiment recording, 3D emotion tracking (Happiness, Energy, Assuredness), Sentiment sharing for teamwork, Elegant and intuitive design, Personal sentiment review over time, Proprietary OSO-Pearl technology

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Los OSO Monthly | $9.99 | per month |
| Los OSO Yearly | $83.00 | per year |


## Frequently asked questions

### Is PDF Viewer by Nutrient free?

PDF Viewer by Nutrient is free to download, with in-app purchases available.

### Is Los OSOs free?

Los OSOs costs $2.99, and also offers in-app purchases.

### Which has better reviews, PDF Viewer by Nutrient or Los OSOs?

Los OSOs is rated higher. PDF Viewer by Nutrient averages 4.6 out of 5 from 9.1K ratings, while Los OSOs averages 5.0 from 1 ratings.

### Do PDF Viewer by Nutrient or Los OSOs have ads?

Neither PDF Viewer by Nutrient nor Los OSOs shows ads.

### Which is updated more often, PDF Viewer by Nutrient or Los OSOs?

PDF Viewer by Nutrient ships an update monthly, and Los OSOs every 6 days. Most recently, PDF Viewer by Nutrient was updated on October 27, 2026 and Los OSOs on October 24, 2026.

---

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