# FM 304 vs PO

The clearest difference is price: PO at Free against FM 304's $3.99. PO also leads on update cadence (every 2 days vs every 43 months) and rating (5.0 vs 4.8). FM 304's advantage is ratings volume (4 vs 1) and iOS requirement (12.0 vs 15.0). On in-app purchases there is nothing between them.

PO is free to download; FM 304 costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

PO holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 4 and 1 respectively.

FM 304 ships an update every 43 months, PO every 2 days. The most recent releases landed on October 2, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | FM 304 | PO |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | [4.8 (4 ratings)](https://appshunter.io/ios/app/fm-304/id1449167984/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/po-patchstudio/id6809190034/reviews)** |
| Number of ratings | **4** | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | — | No |
| Update frequency | Every 43 months | **Every 2 days** |
| Monetization | Paid | **Free** |
| Size | 17 MB | 12 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Paul Betowski](https://appshunter.io/developer/538476580) | [Photon Consulting Limited](https://appshunter.io/developer/6778625337) |

## What reviewers say

### FM 304

[App page](https://appshunter.io/ios/app/fm-304/id1449167984)

Create music with three powerful FM synthesizers, each featuring integrated sequencers and onboard effects. This app offers intuitive real-time control over all synth parameters for quick sound design and tune creation.

**Highlights:** Three 4-operator FM synths, Integrated sequencers, Onboard delay, reverb, and chorus effects, One knob per function control, 100 save slots, 8 algorithms, Note frequency quantize

**In-app purchases:** none


### PO

[App page](https://appshunter.io/ios/app/po-patchstudio/id6809190034)

Design and edit drum sounds, kits, and patterns for Teenage Engineering's PO-32 Tonic. Transfer your creations to the device via audio. Back up and edit existing sounds, and import/export patches from Microtonic.

**Highlights:** Shape 16 sounds with 21 synth parameters, Program 16-step patterns with accents, Send kits, sounds, or patterns via audio, Back up and decode PO-32 data dumps, Import/export Microtonic patches, Local library with tags and favorites

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

**In-app purchases:** none


## Frequently asked questions

### Is FM 304 free?

FM 304 costs $3.99, with no in-app purchases.

### Is PO free?

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

### Which has better reviews, FM 304 or PO?

PO is rated higher. FM 304 averages 4.8 out of 5 from 4 ratings, while PO averages 5.0 from 1 ratings.

### Which is updated more often, FM 304 or PO?

FM 304 ships an update every 43 months, and PO every 2 days. Most recently, FM 304 was updated on October 2, 2026 and PO on October 11, 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.*