Comparison

Stone Echo vs SL Air

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • Frequency changing echo effect
  • Phase modulated frequency
  • Standalone app and AUV3 plugin
  • Adjustable time, feedback, and level
  • UFO mode for experimental sounds
Features
Read full description

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

About

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.

Highlights
  • 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
Features
Read full description

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

Stone Echo2 screens
SL Air3 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard5 real differences · 5 level
Stone Echo versus SL Air: the parameters behind the verdict, then further details
ParameterStone EchoSL Air
Price$2.99 — better$6.99
Rating2.8 (4 ratings)5.0 (1 ratings) — better
Positive reviews50.0% of reviews—
Number of ratings4 — better1
Update frequencyEvery 38 monthsWeekly — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS10.0 — better15.0
Further details — not scored
Size9 MB15 MB
Age rating4+4+
DeveloperAleksandar MlazevVIACHESLAV ZHILTSOV

Customer experience

Stone Echo

All ratings4 ratings
Positive50.0%
Neutral0.0%
Negative50.0%
Written reviews2 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

SL Air

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Stone Echo

No in-app purchases

None

SL Air

No in-app purchases

Questions

Is Stone Echo free?
Stone Echo costs $2.99, with no in-app purchases.
Is SL Air free?
SL Air costs $6.99, with no in-app purchases.
Which has better reviews, Stone Echo or SL Air?
SL Air is rated higher. Stone Echo averages 2.8 out of 5 from 4 ratings, while SL Air averages 5.0 from 1 ratings.
Do Stone Echo or SL Air have ads?
Neither Stone Echo nor SL Air shows ads.
Which is updated more often, Stone Echo or SL Air?
Stone Echo ships an update every 38 months, and SL Air weekly. Most recently, Stone Echo was updated on October 24, 2026 and SL Air on October 25, 2026.

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