# RM vs FormKey

The clearest difference is price: FormKey at Free against RM's $9.99. FormKey also leads on update cadence (fortnightly vs every 10 months). RM's advantage is in-app purchases (none vs 1) and rating (4.6 vs 4.3). On ads, monetization model and device support there is nothing between them.

FormKey is free to download; RM costs $9.99 up front. FormKey sells 1 one-off in-app purchase. RM asks for nothing beyond the download.

RM holds the better App Store score, 4.6 against 4.3. Both are backed by a comparable volume of ratings — 18 and 6 respectively. Written reviews point the same way: 67% of RM's written reviews are positive against 50% of FormKey's.

RM ships an update every 10 months, FormKey fortnightly. Both last shipped on September 19, 2026.

## The numbers

| Metric | RM | FormKey |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | **[4.6 (18 ratings)](https://appshunter.io/ios/app/rm-1-wave-modulator/id1436855751/reviews)** | [4.3 (6 ratings)](https://appshunter.io/ios/app/formkey/id1535350561/reviews) |
| Number of ratings | **18** | 6 |
| Positive reviews | **66.7% of reviews** | 50.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 10 months | **Fortnightly** |
| Monetization | Paid | Paid |
| Size | 35 MB | 86 MB |
| Requires iOS | **9.0** | 18.6 |
| Devices | iPad | iPad |
| Age rating | 4+ | 4+ |
| Developer | [Kai Aras](https://appshunter.io/developer/370820899) | [Polyhedra](https://appshunter.io/developer/1535350563) |

## What reviewers say

### RM

[App page](https://appshunter.io/ios/app/rm-1-wave-modulator/id1436855751)

This audio effect app offers versatile modulation capabilities, including ring, amplitude, phase, and frequency modulation. It features a built-in carrier oscillator, multimode filter, envelope follower, and LFO for creating unique sounds. It can be used standalone or with other audio apps.

**Highlights:** Multiple modulation types (Ring, AM, FM, Phase), Built-in carrier oscillator, Multimode filter (LP, HP, BP), Envelope follower and LFO, Standalone and IAA/Audiobus support, AUv3 plugin compatibility

**Features:** macOS Compatibility

**In-app purchases:** none


### FormKey

[App page](https://appshunter.io/ios/app/formkey/id1535350561)

This app is an intuitive MIDI controller that helps musicians improve by using shapes for notes and colors for octaves. Its unique isomorphic keys aid in pattern recognition and chord discovery, making music creation more accessible.

**Highlights:** Shape-based note input, Color-coded octaves, Isomorphic key layout, Pattern recognition aid, Chord discovery assistance, Future update commitment

**Features:** Family Sharing, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| FormKey Full Unlock | $14.99 | one-time |


## Frequently asked questions

### Is RM free?

RM costs $9.99, with no in-app purchases.

### Is FormKey free?

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

### Which has better reviews, RM or FormKey?

RM is rated higher. RM averages 4.6 out of 5 from 18 ratings, while FormKey averages 4.3 from 6 ratings.

### Do RM or FormKey have ads?

Neither RM nor FormKey shows ads.

### Which is updated more often, RM or FormKey?

RM ships an update every 10 months, and FormKey fortnightly. Most recently, RM was updated on September 19, 2026 and FormKey on September 19, 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.*