# Abo Calculator vs STL Preview

The clearest difference is in-app purchases: Abo Calculator at none against STL Preview's 1. Abo Calculator also leads on ads (none vs shown). STL Preview's advantage is update cadence (every 3 days vs every 26 months). On price, device support and iOS requirement there is nothing between them.

Both are free to download. STL Preview sells 1 one-off in-app purchase. Abo Calculator asks for nothing beyond the download.

Abo Calculator ships an update every 26 months, STL Preview every 3 days. The most recent releases landed on October 25, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Abo Calculator | STL Preview |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 26 months | **Every 3 days** |
| Size | 3 MB | 34 MB |
| Requires iOS | 17.2 | **16.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Daniel Palma](https://appshunter.io/developer/1717035273) | [Enes Akkus](https://appshunter.io/developer/1416782412) |

## What reviewers say

### Abo Calculator

[App page](https://appshunter.io/ios/app/abo-calculator/id6478010582)

**Features:** macOS Compatibility

**In-app purchases:** none


### STL Preview

[App page](https://appshunter.io/ios/app/stl-preview/id6773179410)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $0.49 | one-time |


## Frequently asked questions

### Is Abo Calculator free?

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

### Is STL Preview free?

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

### Do Abo Calculator or STL Preview have ads?

STL Preview shows ads; Abo Calculator does not.

### Which is updated more often, Abo Calculator or STL Preview?

Abo Calculator ships an update every 26 months, and STL Preview every 3 days. Most recently, Abo Calculator was updated on October 25, 2026 and STL Preview on October 24, 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.*