# STL Simple Viewer vs U

The clearest difference is rating: STL Simple Viewer at 4.3 against U's 3.0. STL Simple Viewer also leads on ratings volume (866 vs 2) and review sentiment (17% vs 0%). U's advantage is in-app purchases (none vs 4) and ads (none vs shown). On price, update cadence and device support there is nothing between them.

Both are free to download. STL Simple Viewer sells 4 in-app purchases, starting at $0.99 per 7 days. U asks for nothing beyond the download.

STL Simple Viewer holds the better App Store score, 4.3 against 3.0. That said, the two scores are not equally well evidenced: STL Simple Viewer has 866 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 17% of STL Simple Viewer's written reviews are positive against 0% of U's.

STL Simple Viewer ships an update every 20 months, U every 11 months. The most recent releases landed on September 23, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | STL Simple Viewer | U |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (866 ratings)](https://appshunter.io/ios/app/stl-simple-viewer/id1493598400/reviews)** | [3.0 (2 ratings)](https://appshunter.io/ios/app/u-wavepak-bm/id1503266464/reviews) |
| Number of ratings | **866** | 2 |
| Positive reviews | **17.2% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 20 months | **Every 11 months** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 19 MB | 13 MB |
| Requires iOS | 17.0 | **11.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | +4 | 4+ |
| Developer | [Victor Bovio](https://appshunter.io/developer/327627515) | [MITUTOYO CORPORATION](https://appshunter.io/developer/1503266463) |

## What reviewers say

### STL Simple Viewer

[App page](https://appshunter.io/ios/app/stl-simple-viewer/id1493598400)

Easily view and interact with 3D STL CAD models. Supports various file types and offers advanced rendering options for detailed analysis. Get model information and explore interiors with clipping planes.

**Highlights:** View ASCII and Binary STL files, Load STL from ZIP, Rotate, pan, and zoom, Orthogonal and Perspective modes, Model info (triangle count, bounding box), Rendering options (faces, edges, transparency), Clipping plane for interiors

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro version (1 week plan) | $0.99 | per 7 days |
| Pro version (1 month plan) | $1.99 | per month |
| Remove Ads | $2.99 | one-time |
| Export to OBJ, DAE, DXF, PLY | $3.99 | one-time |

**What reviewers like**

- 🚀 Simple and intuitive viewer
- 👍 Useful viewing options
- 💡 Supports multiple file formats

**What reviewers complain about**

- 🐛 Frequent crashes
- 🔋 High battery consumption
- 🚨 Excessive and intrusive ads
- 🔍 Limited functionality for larger files

**Reported bugs**

- App crashes when opening larger STL files
- Inability to open some file formats
- Ads continue to appear even after paying for ad removal

**Requested features**

- Add ability to save color/lighting settings
- Improve stability and reduce crashes
- Provide an ad-free paid version


### U

[App page](https://appshunter.io/ios/app/u-wavepak-bm/id1503266464)

Streamline your workflow by directly inputting measurements from calipers and micrometers. This application simplifies data collection for process control, making it easier to manage your measurements.

**Highlights:** Direct caliper data input, Direct micrometer data input, Process control functionality, Easy data collection

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is STL Simple Viewer free?

STL Simple Viewer is free to download, with in-app purchases available.

### Is U free?

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

### Which has better reviews, STL Simple Viewer or U?

STL Simple Viewer is rated higher. STL Simple Viewer averages 4.3 out of 5 from 866 ratings, while U averages 3.0 from 2 ratings.

### Do STL Simple Viewer or U have ads?

STL Simple Viewer shows ads; U does not.

### Which is updated more often, STL Simple Viewer or U?

STL Simple Viewer ships an update every 20 months, and U every 11 months. Most recently, STL Simple Viewer was updated on September 23, 2026 and U on September 10, 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.*