# STL Simple Viewer vs Signal Conditioning

The clearest difference is price: STL Simple Viewer at Free against Signal Conditioning's $3.99. STL Simple Viewer also leads on update cadence (every 5 months vs every 21 months). Signal Conditioning's advantage is in-app purchases (none vs 4) and ads (none vs shown). On device support and iOS requirement there is nothing between them.

STL Simple Viewer is free to download; Signal Conditioning costs $3.99 up front. STL Simple Viewer sells 4 in-app purchases, starting at $0.99 per 7 days. Signal Conditioning asks for nothing beyond the download.

STL Simple Viewer ships an update every 5 months, Signal Conditioning every 21 months. The most recent releases landed on November 7, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | STL Simple Viewer | Signal Conditioning |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| Rating | **[4.3 (923 ratings)](https://appshunter.io/ios/app/stl-simple-viewer/id1493598400/reviews)** | — |
| Number of ratings | **923** | — |
| Positive reviews | 18.1% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 5 months** | Every 21 months |
| Monetization | Free with in-app purchases | — |
| Size | 19 MB | 1 MB |
| Requires iOS | 17.0 | **16.1** |
| Devices | iPhone, iPad | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Victor Bovio](https://appshunter.io/developer/327627515) | [Fabrizio Boco](https://appshunter.io/developer/466239616) |

## 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 Pack | $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


### Signal Conditioning

[App page](https://appshunter.io/ios/app/signal-conditioning/id1660983914)

**Features:** Vision Pro support

**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 Signal Conditioning free?

Signal Conditioning costs $3.99, with no in-app purchases.

### Do STL Simple Viewer or Signal Conditioning have ads?

STL Simple Viewer shows ads; Signal Conditioning does not.

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

STL Simple Viewer ships an update every 5 months, and Signal Conditioning every 21 months. Most recently, STL Simple Viewer was updated on November 7, 2026 and Signal Conditioning 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.*