Comparison

Stone Echo vs AU Studio

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

AU Studio

This app acts as a dedicated host for Audio Unit extensions, allowing musicians and developers to inspect, audition, and test installed audio plugins. It provides detailed information about each unit's capabilities and behavior without requiring a full digital audio workstation.

Highlights
  • Scan and catalog installed Audio Units
  • Filter plugins by developer, type, and status
  • Load AUv3 interfaces or use detailed inspector
  • Inspect registry identity, MIDI support, and parameters
  • Route CoreMIDI sources and audition audio effects
  • Monitor runtime CPU and memory usage
  • Built-in manual for guidance
Read full description

AU Studio is a focused Audio Unit host, not a DAW. Open the plug-ins you already own, hear them in seconds, and see exactly what they expose. Made for musicians, sound designers, and Audio Unit developers who need a fast, honest test bench. No session to build, no tracks to arm. Pick a unit from your catalog and its interface opens in a panel of its own, named and sized to the plug-in, with your host controls in a bar above it. Key features: - Scan the instruments, effects, music effects, generators, and MIDI processors already installed on your device: AUv3 on iPhone, iPad, and Apple Vision Pro, plus AUv2 on Mac. - Filter by developer, type, or search text, and hide Apple built-ins to focus on third-party gear. - Open a plug-in's own interface when it ships one, and fall back to a metadata view when it doesn't, with the full inspector always one tap away. - Inspect identity, four-character codes, version, sandbox and cached validation status, MIDI support, busses, parameters, presets, latency, and tail time. - Step through factory presets, then save your own working state without leaving the interface. - Play instruments from the floating MIDI keyboard: notes, pitch bend, mod wheel, auto, mono or poly voicing, a shiftable range, and one-tap panic for stuck notes. Your hardware controller lights up the on-screen keys as you play. - Run a guitar, a microphone, or any channel of your interface through a loaded effect. Pick the device, pick mono or stereo, pick the channels. - Load a track into the floating media player, scrub the waveform, loop a section, and play along with your live input at the same time. - Check a signal path in seconds with the built-in test tone. - Route external CoreMIDI sources in, and send generated MIDI back out to a CoreMIDI destination. - Test MIDI 2 units with automatic, MIDI 1, or MIDI 2 protocol selection: high-resolution notes, registered and per-note controllers, per-note pitch bend, discovered MIDI-CI Profiles, and a monitor showing raw or decoded MIDI going in and coming out. - Choose your output device on Mac, and set sample rate, buffer size, and which MIDI sources are enabled. - Keep host-process CPU and memory in view while you work. - Open unfamiliar plug-ins with less risk. AU Studio asks first when the system does not mark a unit sandbox-safe, and a peak limiter sits across the host output. - Read the built-in manual, fully searchable: discovery, routing, presets, hardware input, floating tools, troubleshooting, and developer notes. What AU Studio is: A focused host for discovering, opening, auditioning, and inspecting the Audio Units already on your device. It answers the practical questions: Is the unit visible? Does it load? Does it have an interface? What busses, parameters, presets, and MIDI capabilities does it expose? Does MIDI reach it? Does audio pass through it? What AU Studio is not: It is not a DAW. No multitrack recording, clip launching, timeline arrangement, piano-roll sequencing, MIDI learn, automation lanes, song export, or mastering tools. AU Studio ships no Audio Unit of its own — no instrument, no effect, no DSP engine. It hosts the units other apps provide and wraps them in host-owned routing, auditioning, and inspection. Discovery uses the system Audio Unit registry. If a provider app is not installed, not enabled, or not visible to the platform, AU Studio cannot invent it. Interface behavior, presets, parameter meaning, MIDI mapping, and DSP results belong to each Audio Unit.

Screenshots

Stone Echo2 screens
AU Studio4 screens

Verdict

The call

The clearest difference is rating: AU Studio at 4.5 against Stone Echo's 2.8. AU Studio also leads on update cadence (monthly vs every 38 months) and review sentiment (67% vs 50%). Stone Echo's advantage is price ($2.99 vs $9.99) and iOS requirement (10.0 vs 17.0). On ratings volume, ads, in-app purchases and monetization model 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 AU Studio $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

AU Studio holds the better App Store score, 4.5 against 2.8. Both are backed by a comparable volume of ratings — 4 and 4 respectively. Written reviews point the same way: 50% of Stone Echo's written reviews are positive against 67% of AU Studio's.

UpkeepUpdate frequency

Stone Echo ships an update every 38 months, AU Studio monthly. The most recent releases landed on November 2, 2026 and November 5, 2026 respectively.

Scorecard5 real differences · 5 level
Stone Echo versus AU Studio: the parameters behind the verdict, then further details
ParameterStone EchoAU Studio
Price$2.99 — better$9.99
Rating2.8 (4 ratings)4.5 (4 ratings) — better
Positive reviews50.0% of reviews66.7% of reviews — better
Number of ratings44
Update frequencyEvery 38 monthsMonthly — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, Mac, Vision Pro — better
Requires iOS10.0 — better17.0
Further details — not scored
Size9 MB7 MB
Age rating4+4+
DeveloperAleksandar MlazevChristian Thompson

Customer experience

Stone Echo

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

AU Studio

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews3 reviews
Positive66.7%
Neutral33.3%
Negative0.0%

In-app purchases

None

Stone Echo

No in-app purchases

None

AU Studio

No in-app purchases

Questions

Is Stone Echo free?
Stone Echo costs $2.99, with no in-app purchases.
Is AU Studio free?
AU Studio costs $9.99, with no in-app purchases.
Which has better reviews, Stone Echo or AU Studio?
AU Studio is rated higher. Stone Echo averages 2.8 out of 5 from 4 ratings, while AU Studio averages 4.5 from 4 ratings.
Do Stone Echo or AU Studio have ads?
Neither Stone Echo nor AU Studio shows ads.
Which is updated more often, Stone Echo or AU Studio?
Stone Echo ships an update every 38 months, and AU Studio monthly. Most recently, Stone Echo was updated on November 2, 2026 and AU Studio on November 5, 2026.

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