# StepPolyArp vs QuadroSphere

The clearest difference is in-app purchases: QuadroSphere at none against StepPolyArp's 2. QuadroSphere also leads on price ($14.99 vs $19.99) and update cadence (every 3 weeks vs every 2 months). StepPolyArp's advantage is ratings volume (48 vs 10). On ads, monetization model and device support there is nothing between them.

StepPolyArp costs $19.99 and QuadroSphere $14.99 up front. StepPolyArp sells 2 one-off in-app purchases. QuadroSphere asks for nothing beyond the download.

QuadroSphere holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 48 and 10 respectively. Written reviews point the same way: 87% of StepPolyArp's written reviews are positive against 100% of QuadroSphere's.

StepPolyArp ships an update every 2 months, QuadroSphere every 3 weeks. The most recent releases landed on September 22, 2026 and September 18, 2026 respectively.

## The numbers

| Metric | StepPolyArp | QuadroSphere |
| --- | --- | --- |
| Price | $19.99 | **$14.99** |
| Rating | [4.8 (48 ratings)](https://appshunter.io/ios/app/steppolyarp/id1361313588/reviews) | **[5.0 (10 ratings)](https://appshunter.io/ios/app/quadrosphere/id6740915664/reviews)** |
| Number of ratings | **48** | 10 |
| Positive reviews | 86.7% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | Paid | Paid |
| Size | 38 MB | 18 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Laurent Colson](https://appshunter.io/developer/381525765) | [4Pockets.com](https://appshunter.io/developer/370131860) |

## What reviewers say

### StepPolyArp

[App page](https://appshunter.io/ios/app/steppolyarp/id1361313588)

This app functions as a real-time polyphonic and polyrhythmic MIDI step arpeggiator and sequencer. It can generate melodic patterns from input or operate as a standalone sequencer. Save and sync unlimited presets with iCloud, featuring extensive customization for patterns and step controllers.

**Highlights:** Standalone app and AUv3 MIDI effect plugin, Arpeggiator and step sequencer modes, Programmable step matrix with transposition lines, Polyrhythmic step controllers, Internal sound bank, Ableton Link and MIDI sync support, Unlimited preset saving with iCloud sync

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Dance Horizons | $4.99 | one-time |
| Analog Sequence | $4.99 | one-time |


### QuadroSphere

[App page](https://appshunter.io/ios/app/quadrosphere/id6740915664)

This audio plugin allows musicians to sculpt immersive soundscapes by controlling stereo placement and effects across four distinct frequency bands. Create dynamic, atmospheric audio with automated movement and morphing between saved settings.

**Highlights:** 4 configurable frequency bands, Control stereo separation, level, and pan per band, Create and morph between 12 snapshots, Modulation control for automated sweeps, Per-band effects (Haas, Delay, Reverb, Chorus, Compressor), Convert mono to pseudo-stereo, MIDI CC control

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is StepPolyArp free?

StepPolyArp costs $19.99, and also offers in-app purchases.

### Is QuadroSphere free?

QuadroSphere costs $14.99, with no in-app purchases.

### Which has better reviews, StepPolyArp or QuadroSphere?

QuadroSphere is rated higher. StepPolyArp averages 4.8 out of 5 from 48 ratings, while QuadroSphere averages 5.0 from 10 ratings.

### Do StepPolyArp or QuadroSphere have ads?

Neither StepPolyArp nor QuadroSphere shows ads.

### Which is updated more often, StepPolyArp or QuadroSphere?

StepPolyArp ships an update every 2 months, and QuadroSphere every 3 weeks. Most recently, StepPolyArp was updated on September 22, 2026 and QuadroSphere on September 18, 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.*