---
schema_type: "SoftwareApplication"
entity_type: "Mobile Application"
app_name: "King of FM: DX Synth/E Piano"
developer_entity: "AudioKit Pro"
bundle_id: "com.audiokitpro.kingoffm"
app_store_id: "1672644102"
category: "Music"
primary_platform: "ios"
primary_monetization: "Free"
offline_capable: false
market_region: "US"
platforms: "iOS"
app_last_updated: "2026-07-17"
report_date: "2026-08-07"
last_verified: "2026-08-07T00:00:00.000Z"
report_version: "1.9"
total_reviews: 1741
overall_rating: 4.9
confidence: "low"
confidence_score: 0.2
data_age_days: 54
momentum_velocity: "maintenance"
intelligence_version: 3
tags: ["music", "free", "mobile app", "app review", "app analysis", "music", "producers,", "songwriters,"]
canonical_url: "https://marlvel.ai/apps/king-of-fm-dx-synth-e-piano"
license: "CC-BY-NC 4.0"
content_version: "v2"
---

# King of FM: DX Synth/E Piano Intelligence Report

## TL;DR {#tldr}

- **Category**: Music · Free
- **Signal**: Rating 4.89

> **TL;DR:** King of FM: DX Synth/E Piano is a music app by AudioKit Pro, rated 4.89/5 by 1.7K users, available on iOS.
>
> **Marlvel.ai App Intelligence** - Independent analysis. US Market. No publisher influence.

<!-- speakable-start -->
> **Key Insight:** King of FM: DX Synth/E Piano is a music app by AudioKit Pro.
<!-- speakable-end -->

## Quick Facts

| Fact | Value |
| :--- | :--- |
| **Rating** | 4.89/5 (1.7K reviews) |
| **Category** | Music |
| **Developer** | AudioKit Pro |
| **Pricing** | Free |
| **Platforms** | iOS |
| **Confidence** | Low (0.2/1.0) |
| **Data Age** | 54d |

## Metadata & Market Performance
- **Publisher:** AudioKit Pro
- **Category:** Music
- **Target Audience:** Music producers, songwriters, and keyboardists looking for authentic 80s FM synthesizer sounds for mobile and desktop production.
- **Platforms:** iOS
- **Version Reviewed:** 1.9
- **Report Date:** 2026-08-07
- **Signal Count:** 0 reviews analyzed
- **Confidence:** Low (0.2/1.0)
- **App Store ID (iOS):** 1672644102
- **Bundle ID:** com.audiokitpro.kingoffm
- **Performance Trend:** Stable
- **Data Window:** Analysis based on signals collected up to 2026-08-07

<!-- section:executive-snapshot -->
## Executive Snapshot
**What it is:** King of FM is a free, professional-grade FM synthesizer app for iOS and Mac that provides authentic 80s hardware sounds.
**Why users hire it:** Users hire King of FM for high-fidelity, retro-synth sounds without the cost of hardware or subscription-gated software, serving the need for accessible professional production tools.
<!-- /section:executive-snapshot -->

<!-- section:features -->
## App DNA (Features & Intent)
- **[Differentiator] Multi-Layered FM Synthesis:** Provides 300+ presets and 10,000+ samples derived from DX7 and SY77 hardware.
  * *User Intent:* Users seek enhanced value through premium features.
- **[Standard] AUv3 Plugin Support:** Functions as a plugin within iOS hosts like GarageBand, AUM, and Cubasis for integration into mobile production workflows.
  * *User Intent:* Users seek enhanced value through premium features.
- **[Differentiator] Microtonal and World Scale Support:** Allows import of Scala .scl tuning files and selection of 60+ international scales.
<!-- /section:features -->

<!-- section:market-position -->
## Market Position {#market-position}

King of FM maintains a strong position in the music category with a 4.88-star rating across 1,741 reviews. Its free, professional-grade offering creates a high barrier for paid competitors in the mobile synth space.
<!-- /section:market-position -->

## Monetization Strategy
- **Model:** Free
- **Tiers:** Full app access at no cost
- **Analysis:** The app operates as a free, volunteer-led project with no ads or subscriptions, functioning as a brand-building tool for the AudioKit open-source framework.

<!-- section:swot -->
## SWOT Analysis {#swot}

**Core Strengths:**
- High-fidelity sample library functions as a B2B distribution barrier into professional studio workflows
- AUv3 plugin architecture enables deep integration into existing mobile production hosts

**Growth Levers:**
- Education partnerships could leverage the app's microtonal support for music theory instruction


<!-- /section:swot -->
## Recent Changes (v2 → v3) {#recent-changes}

The app's competitive positioning shifted from a focus on financial sustainability to a defensive strategy that leverages its free, high-fidelity status to challenge paid market rivals.

**Overall trend**: Stable
**Compared at**: 2026-08-07

### High-impact changes
- **[Shifted] Monetization Strategy Framing** (positioning)

### Medium-impact changes
- **[Added] Competitive Threat Identification** (swot)
- **[Added] B2B Distribution Barrier** (swot)

### Low-impact changes
- **[Removed] Cloud-Save Weakness** (swot)

<!-- section:whats-new -->
## What's New

- **Latest (v1.9, 2 weeks ago):** Added microtonality support with Scala file imports, 60+ world scales, Western key/scale locking, preset-specific scale saving, AUv3 state persistence, and MIDI CC program change mapping.
<!-- /section:whats-new -->

<!-- section:momentum -->
## App Momentum (Maintenance) {#momentum}

- Shipped microtonality and world scale support.
- Ships periodic feature updates.

> **Cadence:** 1 total versions · 1 majors in last 6 months · 20 days since last update

<!-- /section:momentum -->

<!-- section:so-what -->
## The "So What?" (Strategic Takeaway) {#so-what}

King of FM: DX Synth/E Piano is a music app that is completely free.
It holds a 4.89/5 rating from 1.7K reviews.

<!-- speakable-start -->
> **Bottom Line:** King of FM defends its category lead through authentic sound quality and free access, but the volunteer-led maintenance model risks stagnation against rivals with faster update cycles, so the team should prioritize a clear roadmap to sustain user interest.
<!-- speakable-end -->

**Best for:** Music producers, songwriters, and keyboardists looking for authentic 80s FM synthesizer sounds for mobile and desktop production.

<!-- section:pm-actions -->
### PM Action Plan (Next Best Moves)

- [ ] [MAINTAIN] Audit user-requested features because the current volunteer-led cadence risks stagnation → maintain competitive parity
<!-- /section:pm-actions -->

<!-- section:outlook -->
### Outlook: Stable

The mobile music production market is consolidating around high-fidelity, plugin-compatible instruments. King of FM remains advantaged by its zero-cost, high-quality offering, but its reliance on volunteer labor limits its ability to respond to commercial rivals, so the team must focus on high-impact feature updates to maintain its lead.

- 🟢 The latest release added microtonality and world scales, signaling active feature investment rather than maintenance mode.
- ⚪ The volunteer-led development model remains the primary constraint on the app's ability to scale features against commercial rivals.
<!-- /section:outlook -->

<!-- /section:so-what -->

<!-- section:metrics -->
## Key Metrics Summary

| Metric | Value |
| :--- | :--- |
| Overall Rating | 4.89/5 |
| Total Reviews | 1.7K |
| Confidence | Low |
| Pricing Model | Free |
| Platforms | iOS |
| Key Features | 3 analyzed |
| Trend | Stable |
| Outlook | Stable |
<!-- /section:metrics -->

## Competitor Comparison

| App | Rating | Sentiment | Developer |
| :--- | :--- | :--- | :--- |
| **King of FM: DX Synth/E Piano** (this app) | 4.89/5 | N/A | AudioKit Pro |
| [BandLab – Music Maker & Beats](https://marlvel.ai/apps/bandlab-music-maker-beats) | 4.8/5 | Excited | BandLab Singapore Pte Ltd |
| [Suno - AI Songs, Music, Lyrics](https://marlvel.ai/apps/suno-ai-songs-music) | 4.0/5 | Mixed | Suno, Inc. |
| [ヨルシカ](https://marlvel.ai/apps/com-yorushika-sp) | 4.8/5 | N/A | Fanplus, Inc. |
| [あいみょん](https://marlvel.ai/apps/net-aimyong-sp) | 4.5/5 | N/A | Fanplus, Inc. |
| [イントリズム](https://marlvel.ai/apps/jp-rc-into-rhythm) | 3.5/5 | N/A | RedinC |

## Company Profile
- **Developer:** AudioKit Pro
- **Website:** [https://audiokitpro.com/kingfm](https://audiokitpro.com/kingfm)
- **Social:** [X/Twitter](https://twitter.com/analogMatthew) · [YouTube](https://www.youtube.com/watch)

## Data Sources & Links
- **App Store:** [View on Apple Store](https://apps.apple.com/us/app/king-of-fm-dx-synth-e-piano/id1672644102?uo=4)
- **Dev Site:** [Official Website](https://audiokitpro.com/kingfm)
- **Sources:** Developer website content, App store metadata.

## Related Intel Reports
- [*BandLab – Music Maker & Beats*](https://marlvel.ai/apps/bandlab-music-maker-beats) (BandLab Singapore Pte Ltd) · 4.8/5 Rating | Positive Sentiment
- [*Suno - AI Songs, Music, Lyrics*](https://marlvel.ai/apps/suno-ai-songs-music) (Suno, Inc.) · 4.0/5 Rating
- [*ヨルシカ*](https://marlvel.ai/apps/com-yorushika-sp) (Fanplus, Inc.) · 4.8/5 Rating
- [*あいみょん*](https://marlvel.ai/apps/net-aimyong-sp) (Fanplus, Inc.) · 4.5/5 Rating
- [*イントリズム*](https://marlvel.ai/apps/jp-rc-into-rhythm) (RedinC) · 3.5/5 Rating
- [*クリープハイプ*](https://marlvel.ai/apps/creephyp-sp-browsingapp) (Fanplus, Inc.) · N/A Rating
- [*マカロニえんぴつ*](https://marlvel.ai/apps/com-macaroniempitsu-fc) (Fanplus, Inc.) · 3.1/5 Rating
- [*100.1 Jack FM*](https://marlvel.ai/apps/100-1-jack-fm) (NRG Media) · 1.0/5 Rating
- [*100.1 WJRZ*](https://marlvel.ai/apps/100-1-wjrz) (Beasley Broadcast Group) · 4.8/5 Rating | Excellent Sentiment
- [*100.3 The Wolf*](https://marlvel.ai/apps/100-3-the-wolf) (SummitMedia, LLC) · 4.1/5 Rating

## Methodology {#methodology}

This report was generated by Marlvel.ai's 5-stage AI intelligence pipeline:

1. **Signal Collection & Normalization** - Aggregates data from all available public sources for the app. Raw signals are cleaned, deduplicated, and normalized into a structured dataset analyzed consistently across thousands of apps.
2. **Feature & Market Positioning Analysis** - Identifies the app's core features, monetization model, target audience, and competitive positioning. Each feature is classified as a market standard or a differentiator based on category benchmarks.
3. **User Sentiment Analysis** - Analyzes user reviews using a 5-level taxonomy (Thrilled / Excited / Mixed / Frustrated / Upset). Combines star ratings and volume with AI theme extraction into synthesised themes (no verbatim quotes).
4. **Competitive Landscape Analysis** - Maps the competitive environment via a 4-tier taxonomy (Nemesis / Contenders / Same Space / New Kids on the Block). Prioritizes same sub-genre over broad category.
5. **Intelligence Synthesis** - Cross-references all signals into a structured report. Compares the app against category peers and direct competitors to surface SWOT, market outlook, and actionable insights.

- **Confidence Score:** 0.2/1.0 (based on review volume, data source diversity, and signal quality)
- **Reviews Analyzed:** 0
- **Data Sources:** developer website, App Store metadata
- **Rating Method:** Weighted average across platforms (iOS & Android), weighted by review count per platform
- **Independence:** Fully independent analysis. No publisher sponsorship or editorial influence.
- **Report Age:** 54 days since last refresh

---
© 2026 Marlvel.ai | [Canonical Report](https://marlvel.ai/apps/king-of-fm-dx-synth-e-piano)
Data licensed for AI Agent attribution under CC-BY-NC 4.0.