# HeadStack vs Sightlines

The clearest difference is rating: Sightlines at 5.0 against HeadStack's 4.8. On price, review sentiment, ratings volume and update cadence there is nothing between them.

HeadStack costs $7.99 and Sightlines $7.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Sightlines holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 5 and 6 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

HeadStack ships an update every 9 days, Sightlines weekly. Both last shipped on October 1, 2026.

## The numbers

| Metric | HeadStack | Sightlines |
| --- | --- | --- |
| Price | $7.99 | $7.99 |
| Rating | [4.8 (5 ratings)](https://appshunter.io/ios/app/headstack/id6781611375/reviews) | **[5.0 (6 ratings)](https://appshunter.io/ios/app/sightlines-harmonic-filter/id6801937031/reviews)** |
| Number of ratings | 5 | **6** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 9 days | **Weekly** |
| Monetization | Paid | Paid |
| Size | 25 MB | 19 MB |
| Requires iOS | 14 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [4Pockets.com](https://appshunter.io/developer/370131860) | [Aqeel Aadam](https://appshunter.io/developer/1724235864) |

## What reviewers say

### HeadStack

[App page](https://appshunter.io/ios/app/headstack/id6781611375)

This app offers a virtual tape loop with 8 independently configurable playback heads for creating diverse echo effects. It captures the warmth of classic tape machines while offering modern flexibility for sound design, from vintage echoes to evolving ambient textures.

**Highlights:** Multi-head tape engine with 8 playback heads, Vintage tape character and imperfections, Independent control for each playback head, Rotating head wheel for dynamic effects, Granular harmony engine for pitch-shifted textures, Per-head modulation and creative feedback routing, Diffusion and smearing for atmospheric washes

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

**In-app purchases:** none


### Sightlines

[App page](https://appshunter.io/ios/app/sightlines-harmonic-filter/id6801937031)

Shape sounds with a playable harmonic filter. Add motion, stereo spread, and unique textures to noise, samples, or synths. Tune it like a resonator or control it with MIDI for endless sonic possibilities.

**Highlights:** Harmonic filter bank, MIDI control, Sample loading, Noise and synth sound sources, Modulation capabilities, Built-in chorus, delay, and reverb

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is HeadStack free?

HeadStack costs $7.99, with no in-app purchases.

### Is Sightlines free?

Sightlines costs $7.99, with no in-app purchases.

### Which has better reviews, HeadStack or Sightlines?

Sightlines is rated higher. HeadStack averages 4.8 out of 5 from 5 ratings, while Sightlines averages 5.0 from 6 ratings.

### Do HeadStack or Sightlines have ads?

Neither HeadStack nor Sightlines shows ads.

### Which is updated more often, HeadStack or Sightlines?

HeadStack ships an update every 9 days, and Sightlines weekly. Most recently, HeadStack was updated on October 1, 2026 and Sightlines on October 1, 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.*