# ZDS vs Heirloom

The clearest difference is in-app purchases: ZDS at none against Heirloom's 2. ZDS also leads on device support (3 vs 1) and iOS requirement (15.1 vs 17.0). Heirloom's advantage is update cadence (every 3 weeks vs every 2 months). On price and ads there is nothing between them.

Both are free to download. Heirloom sells 2 in-app purchases, starting at $8.99 per 7 days. ZDS asks for nothing beyond the download.

ZDS ships an update every 2 months, Heirloom every 3 weeks. The most recent releases landed on October 24, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | ZDS | Heirloom |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 62.5% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | Free | — |
| Size | 30 MB | 10 MB |
| Requires iOS | **15.1** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Zentralverband Deutscher Schornsteinfeger e.V. - Gewerkschaft & Fachverband -](https://appshunter.io/developer/1467613841) | [Randy Torres](https://appshunter.io/developer/1871953838) |

## What reviewers say

### ZDS

[App page](https://appshunter.io/ios/app/zds/id1467613842)

This app serves as a professional resource for chimney sweeps in Germany, offering tools for time tracking, access to legal texts and news, event listings, and job opportunities. Members can also find contact information and view practical videos.

**Highlights:** Time tracking and sharing, Access to legal texts and tariffs, News and event listings, Job market and district listings, Contact finder, Practical videos, Access to training certificates

**Features:** macOS Compatibility

**In-app purchases:** none


### Heirloom

[App page](https://appshunter.io/ios/app/heirloom-old-letter-reader/id6792422170)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Heirloom Weekly | $8.99 | per 7 days |
| Heirloom Yearly | $49.99 | per year |


## Frequently asked questions

### Is ZDS free?

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

### Is Heirloom free?

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

### Do ZDS or Heirloom have ads?

Neither ZDS nor Heirloom shows ads.

### Which is updated more often, ZDS or Heirloom?

ZDS ships an update every 2 months, and Heirloom every 3 weeks. Most recently, ZDS was updated on October 24, 2026 and Heirloom on October 29, 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.*