# FM Synthesizer – Piano Keys — Music frequency changer

> Music frequency changer for sound synthesis and audio creation. (iPhone/iPad app by Stanislav Duplinskiy.)

- Source: https://appshunter.io/ios/app/fm-synthesizer-piano-keys/id1563962952 (this page in markdown: same URL + `.md`)
- Developer: [Stanislav Duplinskiy](https://appshunter.io/developer/1529735040)
- Category: Music, Utilities
- Price: Free with in-app purchases
- Rating: 1.67/5 from 6 App Store ratings · 4 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.0 · 78 MB
- Languages: English
- Released: 2021-04-21
- Data updated: 2026-07-17
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/fm-synthesizer-piano-keys/id1563962952/reviews.md

## What is FM Synthesizer?

Complete immersion in the world of frequency sound synthesis!
Adjust the parameters and get a new sound.

What does the app offer?
- New presets from TOP sound producers every month;
- Multi-genre synths;
- Settings for groups of effects;
- Access to the recording 
of your creative sessions;
- Ability to share your recordings
with friends;

privacy policy: https://sites.google.com/view/castles-trip-privacy-policy 

terms of use: https://sites.google.com/view/fm-synthesizer

## Key features

- Adjustable synthesis parameters
- Monthly new presets
- Multi-genre synths
- Effect group settings
- Session recording
- Share recordings

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Pro access and monthly updates | $9.99 | per month |
| Pro access and monthly updates | $4.99 | per month |

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Effects & Recording | $7.99 | one-time |


## Recent user reviews (4 of 4)

All indexed reviews: https://appshunter.io/ios/app/fm-synthesizer-piano-keys/id1563962952/reviews.md

### 1/5 — Awful

*2024-10-22*

Don’t waste your time with this one.

**Developer response:** Hello, Kennyvert! I’m sorry to hear the app didn’t meet your expectations. Our goal is to offer a unique FM Synthesizer experience, with versatile presets and detailed waveform controls. If there’s any specific feature or improvement you’d like to see, please feel free to share. We’re always looking to enhance the app and make it more enjoyable for users.

### 5/5 — Cool app

*2023-10-23*

I’m really enjoying this app

**Developer response:** Hello!
Thank you for your feedback :)

### 1/5 — Don’t believe in renting apps

*2023-08-21*

And neither should you as a consumer,

**Developer response:** Hi, zyberpunk!

Thank you very much for your feedback, it is important to us.
We really had difficulty releasing updates and had to rewrite the engine.
Everything will be ready soon.
We are sorry that you had a negative experience.
We are working on updates.

Best regards, Castles Trip

### 1/5 — Doesn't work

*2021-12-14*

Tapping the keys does absolutely nothing. The control knobs turn, but I never got it to make a single sound. And almost everything you tap brings up a screen asking you to "subscribe".  Subscribe to what? A broken app?

**Developer response:** Thank you for your feedback!
We will be very grateful if you report the version of the application, the version of the axis on which you noticed this problem and the device.
We will definitely check and fix this error!

To contact us, we ask you to write a letter to castles.trip.spprt@gmail.com.

## Frequently asked questions about FM Synthesizer

### What is FM Synthesizer?

FM Synthesizer is a music app that allows users to explore sound synthesis by adjusting various parameters to create new and unique sounds. It offers multi-genre synths and effect group settings.

### Does FM Synthesizer have ads?

No, FM Synthesizer does not contain advertisements. The app is free to download and use, with optional in-app purchases for additional features or content.

### How often are new presets added to FM Synthesizer?

FM Synthesizer offers new presets from top sound producers every month. These updates aim to provide users with fresh sonic palettes for their creative sessions.

### Can I record and share my music with FM Synthesizer?

Yes, FM Synthesizer allows you to record your creative sessions and provides the ability to share these recordings with your friends. This feature facilitates collaboration and showcasing your musical ideas.

### What are the subscription options for FM Synthesizer?

FM Synthesizer offers Pro access with monthly updates through subscription plans. Options include $4.99/month or $9.99/month, both with a 3-day free trial.

### What devices is FM Synthesizer compatible with?

FM Synthesizer is compatible with iPhone, iPad, and iPod devices. It is designed to run on Apple's mobile operating systems.

### What is the age rating for FM Synthesizer?

FM Synthesizer has an age rating of 4+. This indicates that the content is generally suitable for young children, though parental guidance is always recommended.

### When was FM Synthesizer last updated?

The latest version of FM Synthesizer, 1.4.0, was last updated on December 16, 2021. The app was initially released on April 21, 2021.

## Version history (last 5 releases)

### 1.4.1 — 2026-06-29

- Added a new octave, covering even more notes
- Save your own custom presets
- Expanded the built-in presets library
- Added a recording timer for easy tracking
- New, convenient preset selection screen
- Add presets to your favorites
- Performance optimizations
- Minor bug fixes

### 1.4.0 — 2021-12-16

Added new presets.
Appeared design settings.
Minor bugs fixed.

### 1.1.3 — 2021-06-03

Minor bugs fixed.

### 1.1.2 — 2021-06-01

Minor bugs fixed.

### 1.1.1 — 2021-05-09

Minor bugs fixed.
Presets update.

## Apps similar to FM Synthesizer

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [AudioKit Synth One Synthesizer](https://appshunter.io/ios/app/audiokit-synth-one-synthesizer/id1371050497) | 4.9 (26,820) | Free | Music |
| [E Piano Synth - Keyboard Tiles](https://appshunter.io/ios/app/e-piano-synth-keyboard-tiles/id1513122706) | 4.4 (32) | Free | Music |
| [Synth Pro: Analog Synthesizer](https://appshunter.io/ios/app/synth-pro-analog-synthesizer/id1635988723) | 4.6 (469) | Free | Music |
| [Piano ٞ](https://appshunter.io/ios/app/piano/id1126477246) | 4.6 (167,637) | Free | Music |
| [Piano Keyboard App: Play Songs](https://appshunter.io/ios/app/piano-keyboard-app-play-songs/id1171389552) | 4.5 (11,765) | Free | Music |
| [Piano Pro & Drum Music Studio](https://appshunter.io/ios/app/piano-pro-and-drum-music-studio/id1563206106) | 4.6 (1,298) | Free | Music |

## More apps by Stanislav Duplinskiy

- [My Kalimba - Relax Meditation](https://appshunter.io/ios/app/my-kalimba-relax-meditation/id1529735038)
- [Granular Synthesizer](https://appshunter.io/ios/app/granular-synthesizer/id1537443140)
- [Night Light - Calm Sleep](https://appshunter.io/ios/app/night-light-calm-sleep/id1546253241)
- [Light Vibes](https://appshunter.io/ios/app/light-vibes/id1549938712)
- [OIIIO – Lab Arpeggiator](https://appshunter.io/ios/app/oiiio-lab-arpeggiator/id1569332170)

All apps by Stanislav Duplinskiy: https://appshunter.io/developer/1529735040

## Related topics

[synthesizer fm](https://appshunter.io/ios/topics/synthesizer-fm)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-17.*