Stone Echo vs SL Air
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Stone Echo
This app creates a unique echo effect with adjustable frequency modulation, inspired by Mayan pyramid acoustics. It offers musical and experimental soundscapes, functioning as a standalone application or an AUV3 plugin.
- Frequency changing echo effect
- Phase modulated frequency
- Standalone app and AUV3 plugin
- Adjustable time, feedback, and level
- UFO mode for experimental sounds
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Echo effect Audio Unit V3 inspired by the mayan pyramids acoustic echo. I come up with a complex phase modulated frequency of the echo so you can change it’s frequency signature. It is kind of changing the material of the reflective surface and I called it “Stone F”. I have made the echo to sound more music friendly to me but there is button called “UFO” and if you press it the effect is more close to the mayan just shifting the frequency backwards (I liked that better). You can also control the feedback of the phase modulation. The effect can work as a stand alone app and as an audio unit AUV3 plug-in. Stone Echo is an effect that is heavy on the CPU Controls: - Time - time offset of the echo - Stone F - frequency response of the echo - Feedback - echo feedback - Level - the volume of the echo - UFO - heavy modulated echo
SL Air
Enhance your audio with this AUv3 effect, designed to add brightness, presence, and stereo width. Achieve a polished top-end for vocals, drums, samples, and full mixes with intuitive controls and a motion display.
- Controlled brightness (Air & Lift)
- Smoother high-frequency detail (Silk)
- Stereo expansion (Wide)
- Polished finish (Glow)
- Audio-reactive motion display
- Factory and user presets
- AUv3 support
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SL Air is a streamlined AUv3 audio effect for adding brightness, presence, stereo width and a polished top end to vocals, drums, samples and mixes. • Air and Lift for controlled brightness • Silk for smoother high-frequency detail • Wide for stereo expansion • Glow for a polished finish • Audio-reactive motion display • Factory presets and local user presets • AUv3 support for compatible iPad music hosts Works as a standalone preview app and as an AUv3 effect in GarageBand, AUM, Cubasis, BeatMaker 3 and other compatible hosts.
Screenshots
Verdict
The clearest difference is rating: SL Air at 5.0 against Stone Echo's 2.8. SL Air also leads on update cadence (weekly vs every 38 months). Stone Echo's advantage is price ($2.99 vs $6.99) and ratings volume (4 vs 1). On ads, in-app purchases, monetization model and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Stone Echo costs $2.99 and SL Air $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.
SL Air holds the better App Store score, 5.0 against 2.8. Both are backed by a comparable volume of ratings — 4 and 1 respectively.
Stone Echo ships an update every 38 months, SL Air weekly. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.
| Parameter | Stone Echo | SL Air |
|---|---|---|
| Price | $2.99 — better | $6.99 |
| Rating | 2.8 (4 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 4 — better | 1 |
| Update frequency | Every 38 months | Weekly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 10.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 9 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | Aleksandar Mlazev | VIACHESLAV ZHILTSOV |
Customer experience
Stone Echo
SL Air
In-app purchases
Stone Echo
No in-app purchases
SL Air
No in-app purchases









