# ISD2go vs Katzenmusik

The clearest difference is update cadence: ISD2go at fortnightly against Katzenmusik's every 24 months. ISD2go also leads on device support. Katzenmusik's advantage is iOS requirement (12.4 vs 17.0). On price and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ISD2go ships an update fortnightly, Katzenmusik every 24 months. The most recent releases landed on October 29, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | ISD2go | Katzenmusik |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | — |
| Update frequency | **Fortnightly** | Every 24 months |
| Size | 84 MB | 13 MB |
| Requires iOS | 17.0 | **12.4** |
| Devices | **iPhone, iPad** | — |
| Age rating | 4+ | 4+ |
| Developer | [ISD Immobilien Service Deutschland GmbH & Co. KG](https://appshunter.io/developer/1509634573) | [Katzenmusik Verein "Miau" Villingen 1872 e.V.](https://appshunter.io/developer/1748548442) |

## What reviewers say

### ISD2go

[App page](https://appshunter.io/ios/app/isd2go/id1509634574)

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

**In-app purchases:** none


### Katzenmusik

[App page](https://appshunter.io/ios/app/katzenmusik/id6503244850)

**In-app purchases:** none


## Frequently asked questions

### Is ISD2go free?

ISD2go is free to download, with no in-app purchases.

### Is Katzenmusik free?

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

### Which is updated more often, ISD2go or Katzenmusik?

ISD2go ships an update fortnightly, and Katzenmusik every 24 months. Most recently, ISD2go was updated on October 29, 2026 and Katzenmusik 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.*