# Undersong vs Bent Spool

The clearest difference is price: Bent Spool at Free against Undersong's $9.99. Undersong's advantage is in-app purchases (none vs 1) and chart position (#112 vs unranked). On rating, ratings volume, update cadence and ads there is nothing between them.

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

On the App Store both sit at effectively the same score — 5.0 for Undersong against 5.0 for Bent Spool. Both are backed by a comparable volume of ratings — 11 and 5 respectively.

Both ship on a similar rhythm, roughly daily. Both last shipped on October 31, 2026.

## The numbers

| Metric | Undersong | Bent Spool |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | [5.0 (11 ratings)](https://appshunter.io/ios/app/undersong/id6802013758/reviews) | [5.0 (5 ratings)](https://appshunter.io/ios/app/bent-spool/id6811386417/reviews) |
| Number of ratings | **11** | 5 |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Daily | Daily |
| Monetization | Paid | **Free with in-app purchases** |
| Best chart rank | **#112** | — |
| Size | 19 MB | 23 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [ian johnston](https://appshunter.io/developer/1886071653) | [Plastic Factory LLC](https://appshunter.io/developer/1017920807) |

## What reviewers say

### Undersong

[App page](https://appshunter.io/ios/app/undersong/id6802013758)

**Currently charting:** #112 Top Paid · Music (US App Store)

This audio effect acts like an instrument, generating synthesized notes in key based on incoming audio. Explore a vast array of sound combinations with various materials, modes, and patterns for unique ambient performances.

**Highlights:** Generates in-key synthesized notes from audio input, 12 material types and 10 performance modes, 10 pattern options for sound shaping, Self-generating ambient pad mode, Gravity feature for melodic anchoring, Customizable scales and root notes, Integrated reverb effect

**In-app purchases:** none


### Bent Spool

[App page](https://appshunter.io/ios/app/bent-spool/id6811386417)

This music app offers creative audio effects for live performance or use within other music apps. Explore rhythmic tremolo, pitched repeats, and looping fragments of your audio. It includes built-in overdrive and tape effects for unique sound shaping.

**Highlights:** Rhythmic tremolo effects, Pitched repeat sequences, Overlapping audio loops, Built-in overdrive and fuzz, Vintage tape effects, Standalone and AUv3 host support

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Bent Spool Unlock | $9.99 | one-time |


## Frequently asked questions

### Is Undersong free?

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

### Is Bent Spool free?

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

### Which has better reviews, Undersong or Bent Spool?

Undersong and Bent Spool are both rated 5.0 out of 5 on the App Store, from 11 and 5 ratings respectively.

### Do Undersong or Bent Spool have ads?

Neither Undersong nor Bent Spool shows ads.

### Which is updated more often, Undersong or Bent Spool?

Undersong ships an update daily, and Bent Spool daily. Most recently, Undersong was updated on October 31, 2026 and Bent Spool on October 31, 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.*