# Harmonius vs Key Lens

The clearest difference is in-app purchases: Harmonius at none against Key Lens's 1. On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Key Lens sells 1 one-off in-app purchase. Harmonius asks for nothing beyond the download.

## The numbers

| Metric | Harmonius | Key Lens |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | — | Every 5 weeks |
| Size | 152 MB | 64 MB |
| Requires iOS | 17.0 | **16.4** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Lorenzo Brown](https://appshunter.io/developer/1496868083) | [Alex Amayo](https://appshunter.io/developer/1835625743) |

## What reviewers say

### Harmonius

[App page](https://appshunter.io/ios/app/harmonius/id6499569641)

**Features:** macOS Compatibility

**In-app purchases:** none


### Key Lens

[App page](https://appshunter.io/ios/app/key-lens/id6761850903)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Midi Output | $9.99 | one-time |


## Frequently asked questions

### Is Harmonius free?

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

### Is Key Lens free?

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

### Do Harmonius or Key Lens have ads?

Neither Harmonius nor Key Lens shows ads.

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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.*