Stone Echo vs pOus
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
pOus
This app emulates analog drum machine bass drums with adjustable tuning and decay. It offers MIDI OUT functionality for envelope follower data and a scale mode for playing musical scales. Designed for musicians using AUv3 hosts.
- BassDrum emulation
- Adjustable tune and decay
- MIDI OUT envelope follower
- Scale mode for musical notes
- AUv3 instrument
- MIDI CC routing
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Concept: The app is an AUv3 instrument that emulates the so-called “BassDrum” of analog drum machine. In addition it features MIDI OUT functionality of Envelop Follower, that is, the user can send out this instrument's unique envelop via midi CC for modulating external plugins. Also there is "scale mode" where the user can play "pOus" with musical scale like Bass. System Requirements: AUv3 host that has a flexible capability of MIDI routing (AUM, apeMatrix, etc) Usage: There are 9 sliders & one button. Tune: BassDrum’s fundamental frequency (30hz - 160hz). text-editable. Decay: determines its duration. Amp: audio’s decibel representation. MIDI OUT: whether the functionality of envelop follower is turned on or off (default: off) MIDI Gain: gain amount of MIDI out Offset: balances the output parameter’s value Channel: determines MIDI channel MIDI CC: determines the destination MIDI CC number. text-editable Scale Mode: This is a sort of Bass mode, that is, it can play musical scale in response to incoming MIDI notes. Button: triggers the instrument. Recommended Scheme: drum machine (MIDI out) -> “pOus” -> audio effect (compressor, saturator etc)
Screenshots
Verdict
The clearest difference is rating: pOus at 5.0 against Stone Echo's 2.8. pOus also leads on update cadence (every 4 months vs every 38 months). Stone Echo's advantage is ratings volume (4 vs 1) and iOS requirement (10.0 vs 12.0). On price, 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
Stone Echo costs $2.99 and pOus $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
pOus 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, pOus every 4 months. The most recent releases landed on November 11, 2026 and October 30, 2026 respectively.
| Parameter | Stone Echo | pOus |
|---|---|---|
| Price | $2.99 | $2.99 |
| 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 | Every 4 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 10.0 — better | 12.0 |
| Further details — not scored | ||
| Size | 9 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | Aleksandar Mlazev | Satoshi Kajii |
Customer experience
Stone Echo
pOus
In-app purchases
Stone Echo
No in-app purchases
pOus
No in-app purchases









