# Spool Tracker vs STL Viewer

Spool Tracker and STL Viewer are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Both are free to download. Spool Tracker sells 2 in-app purchases, starting at $4.99 per month and STL Viewer sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Spool Tracker ships an update fortnightly, STL Viewer every 8 days. The most recent releases landed on October 1, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Spool Tracker | STL Viewer |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Fortnightly | **Every 8 days** |
| Size | 36 MB | 39 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 12+ |
| Developer | [Three19 Pty Ltd](https://appshunter.io/developer/1873148699) | [Mohamed Nagy](https://appshunter.io/developer/1582361271) |

## What reviewers say

### Spool Tracker

[App page](https://appshunter.io/ios/app/spool-tracker-spoolvault/id6758485486)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SpoolVault Premium | $4.99 | per month |
| SpoolVault Premium | $49.99 | per year |


### STL Viewer

[App page](https://appshunter.io/ios/app/stl-viewer-3d-model-and-print/id6769513616)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime | $12.99 | one-time |


## Frequently asked questions

### Is Spool Tracker free?

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

### Is STL Viewer free?

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

### Do Spool Tracker or STL Viewer have ads?

Neither Spool Tracker nor STL Viewer shows ads.

### Which is updated more often, Spool Tracker or STL Viewer?

Spool Tracker ships an update fortnightly, and STL Viewer every 8 days. Most recently, Spool Tracker was updated on October 1, 2026 and STL Viewer on October 25, 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.*