# iDousyn vs Rainbow Keys

The clearest difference is review sentiment: Rainbow Keys at 100% against iDousyn's 34%. Rainbow Keys also leads on price (Free vs $3.99) and in-app purchases (none vs 1). On ads, monetization model and device support there is nothing between them.

Rainbow Keys is free to download; iDousyn costs $3.99 up front. iDousyn sells 1 one-off in-app purchase. Rainbow Keys asks for nothing beyond the download.

iDousyn ships an update every 2 months, Rainbow Keys every 4 days. The most recent releases landed on November 10, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | iDousyn | Rainbow Keys |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | **[4.2 (161 ratings)](https://appshunter.io/ios/app/idousyn/id421852860/reviews)** | — |
| Number of ratings | **161** | — |
| Positive reviews | 34.1% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 4 days** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 1.2 GB | 34 MB |
| Requires iOS | 26.0 | **17** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Jorge Lozada](https://appshunter.io/developer/421852863) | [Matthew Sefton](https://appshunter.io/developer/1726261512) |

## What reviewers say

### iDousyn

[App page](https://appshunter.io/ios/app/idousyn/id421852860)

This app transforms your device into a professional music production tool. It features a sample-based synthesizer with dual-layer sampling, advanced filters, and a professional effects chain. Create immersive sounds and build captivating tracks with an intuitive interface and extensive sound library.

**Highlights:** Dual-layer sampling, Advanced filters and EQ, Professional effects chain, Creative chord pads, MIDI mastery, Expansive sound library

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Pro | Free | one-time |

**What reviewers like**

- 👍 Good clean sounds
- 👍 Simple to use
- 👍 Low CPU usage
- 👍 Sounds great
- 👍 Great piano and strings app

**What reviewers complain about**

- 🐛 Ads pop up making it unplayable
- 🐛 Full version still displays full-page ads
- 🐛 Ads appear on the front page
- 🐛 Ads are annoying
- 🐛 Totally unusable product

**Reported bugs**

- App crashes immediately
- Full version displays full-page ads
- Ads appear on the front page
- New update has ads
- Implemented trackers

**Requested features**

- Adaptive Crasher (AUV3, Adaptive Cubasis and Zenbeats)
- AUV3 support
- Audiobus compatibility
- MIDI IN for better keyboard control
- Background audio option


### Rainbow Keys

[App page](https://appshunter.io/ios/app/rainbow-keys/id6476235636)

Learn piano scales and chords with augmented reality. This app overlays key names onto your keyboard, aiding real-time learning for improvisation and music theory.

**Highlights:** Augmented reality key display, Object recognition for keyboards, Selectable scales and chords, Real-time learning, Music theory education, Improvisation aid

**In-app purchases:** none


## Frequently asked questions

### Is iDousyn free?

iDousyn costs $3.99, and also offers in-app purchases.

### Is Rainbow Keys free?

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

### Do iDousyn or Rainbow Keys have ads?

Neither iDousyn nor Rainbow Keys shows ads.

### Which is updated more often, iDousyn or Rainbow Keys?

iDousyn ships an update every 2 months, and Rainbow Keys every 4 days. Most recently, iDousyn was updated on November 10, 2026 and Rainbow Keys on November 4, 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.*