Sirens' Chor vs EvilTwin
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Sirens' Chor
This experimental audio effect app analyzes input audio to generate a secondary harmonic voice using sine wave oscillators. The generated voice can be mixed with the original or played solo, creating a chorus effect. It's CPU intensive and operates within a specific frequency range.
- Harmonic analysis of input audio
- Sine wave oscillator synthesis
- Adjustable chorus effect
- Second voice generation
- AUV3 plugin support
Read full descriptionHide full description
This one is quite experimental and CPU heavy app! While working on my Chord Detector app I came up with the idea to play the found harmonics with sine wave oscillators so I can hear what the algorithm is hearing :) It turns out to be an interesting output that led me to creation of this audio effect app. What happens here is that the input is analysed for main harmonics in the range of 80Hz to 1500Hz. Then a series of sine wave oscillators are set to play those harmonics with the exact frequency and volume and their output is added to create a second voice. This second voice can then be mixed with the input to create some kind of chorus or played alone. All this is CPU heavy process so it should be used with care... Also to make this effect possible I had to use limited range 80Hz to 1500Hz so it is not suitable for every instrument and you have to keep that range in mind when producing. Some very fast volume and frequency changes are applied to the oscillators. The app is AUV3
EvilTwin
This audio effect plugin adds width, motion, and unique character to your sound. It offers creative stereo enhancement and dynamic spatial animation, suitable for subtle polish or dramatic transformations. Designed for musicians and sound designers, it encourages sonic exploration with a focused interface.
- Creative stereo enhancement and widening
- Dynamic movement and spatial animation
- Subtle-to-extreme sound shaping
- Performance-focused interface
- AUv3 support for iPad and Mac
- Works with popular music hosts
Read full descriptionHide full description
Evil Twin is a creative stereo processing effect designed to add width, motion, depth, and unexpected character to your sound. Built for musicians, producers, sound designers, and experimental artists, Evil Twin combines stereo enhancement with controlled instability, allowing you to move from subtle spatial polish to dramatic transformations with a simple and focused interface. Whether you're widening a synth, adding movement to a pad, creating animated textures, or pushing sounds into unfamiliar territory, Evil Twin encourages exploration while remaining fast and musical to use. Features: • Creative stereo enhancement and widening • Dynamic movement and spatial animation • Subtle-to-extreme sound shaping possibilities • Simple, performance-focused interface • AUv3 support for iPad and Mac • Works in compatible hosts including GarageBand, Logic Pro, AUM, Cubasis, and Audiobus Evil Twin is designed for creators who enjoy discovering new sounds rather than following predictable presets. Sometimes the best results happen when things drift a little off course. Basic usage guide at folinaaudio.com.
Screenshots
Verdict
The clearest difference is rating: EvilTwin at 5.0 against Sirens' Chor's 4.0. EvilTwin also leads on price ($2.99 vs $3.99). Sirens' Chor's advantage is iOS requirement (10.0 vs 12.0). On review sentiment, ratings volume, ads and in-app purchases 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
Sirens' Chor costs $3.99 and EvilTwin $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
EvilTwin holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 2 and 2 respectively. Written reviews split almost evenly too, at 100% and 100% positive.
| Parameter | Sirens' Chor | EvilTwin |
|---|---|---|
| Price | $3.99 | $2.99 — better |
| Rating | 4.0 (2 ratings) | 5.0 (2 ratings) — better |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 2 | 2 |
| Update frequency | Every 39 months | — |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 10.0 — better | 12.0 |
| Further details — not scored | ||
| Size | 11 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | Aleksandar Mlazev | Jeremy Phillips |
Customer experience
Sirens' Chor
EvilTwin
In-app purchases
Sirens' Chor
No in-app purchases
EvilTwin
No in-app purchases









