# In Theory vs luapsel

The clearest difference is rating: In Theory at 5.0 against luapsel's 4.5. luapsel's advantage is price ($0.99 vs $4.99). On ratings volume, update cadence, ads and in-app purchases there is nothing between them.

In Theory costs $4.99 and luapsel $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

In Theory holds the better App Store score, 5.0 against 4.5. Both are backed by a comparable volume of ratings — 4 and 4 respectively.

In Theory ships an update weekly, luapsel every 6 days. Both last shipped on October 24, 2026.

## The numbers

| Metric | In Theory | luapsel |
| --- | --- | --- |
| Price | $4.99 | **$0.99** |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/in-theory-interval-keyboard/id1667984658/reviews)** | [4.5 (4 ratings)](https://appshunter.io/ios/app/luapsel/id6569224196/reviews) |
| Number of ratings | 4 | 4 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Weekly | **Every 6 days** |
| Monetization | Paid | Paid |
| Size | 7 MB | 101 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Cem Olcay](https://appshunter.io/developer/523633853) | [OSC Audio](https://appshunter.io/developer/1693533681) |

## What reviewers say

### In Theory

[App page](https://appshunter.io/ios/app/in-theory-interval-keyboard/id1667984658)

This app provides a unique interval-based MIDI keyboard with over 110 scales. It allows for flexible chord creation by toggling additional intervals and notes from different octaves. It integrates with external MIDI keyboards and sequencers for advanced music production.

**Highlights:** Interval-based MIDI keyboard, Over 110 built-in scales, Customizable chord voicing, MIDI keyboard input support, MIDI CC message control, AUv3 plugin compatibility, Visual scale and note display

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

**In-app purchases:** none


### luapsel

[App page](https://appshunter.io/ios/app/luapsel/id6569224196)

Create calming electric guitar ambience with reversed samples and built-in effects. Offers polyphonic playback, multiple articulations, and real-time sound shaping tools for unique musical textures.

**Highlights:** Polyphonic reversed guitar sounds, Round Robin sampling, Multiple articulations, Built-in delay, reverb, chorus, Real-time low-pass filter, ADSR Release control, Standalone samples available

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

**In-app purchases:** none


## Frequently asked questions

### Is In Theory free?

In Theory costs $4.99, with no in-app purchases.

### Is luapsel free?

luapsel costs $0.99, with no in-app purchases.

### Which has better reviews, In Theory or luapsel?

In Theory is rated higher. In Theory averages 5.0 out of 5 from 4 ratings, while luapsel averages 4.5 from 4 ratings.

### Do In Theory or luapsel have ads?

Neither In Theory nor luapsel shows ads.

### Which is updated more often, In Theory or luapsel?

In Theory ships an update weekly, and luapsel every 6 days. Most recently, In Theory was updated on October 24, 2026 and luapsel on October 24, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*