FAC Chorus vs StringLab
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
FAC Chorus
This app delivers an authentic, lush, and organic chorus effect with analog-style circuitry. It offers versatile modulation, from subtle doubling to rich swirling sounds, and can function as a chorus, flanger, or vibrato. Expanded controls and feedback options provide deep sonic shaping for professional music production.
- Authentic analog-style bucket brigade circuitry
- Subtle doubling to rich swirling modulation
- Chorus, Flanger, or Vibrato modes
- Expanded controls with multiple characters
- Feedback control for flanger-like textures
- AUv3 plugin for iOS, macOS, and Vision Pro
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• Authentic, lush, and organic chorus effect • True analog-style bucket brigade circuitry • A modern reissue of the most iconic hardware units • Ranges from subtle doubling to rich, swirling modulation • Versatile usage: Chorus, Flanger, or Vibrato • Expanded controls with multiple characters and waveforms • Feedback control for rich, flanger-like textures • A favorite chorus in the iOS music community • Advanced Responsive Design, portrait and landscape views • Universal Purchase: AUv3 for iOS (iPad/iPhone), macOS and Vision Pro FAC Chorus brings depth and movement to your sounds with an authentic, lush, and organic character. Built with true analog-style bucket brigade circuitry, this plugin is a modern reissue of some of the most iconic hardware units, faithfully capturing their distinctive tone. The effect ranges from subtle doubling to rich, swirling modulation, covering different uses as a Chorus, Flanger, or Vibrato. The expanded modulation controls, multiple characters, and LFO waveforms allow precise shaping of your sound, giving you complete creative flexibility. In addition, the feedback control adds rich, flanger-like textures for dynamic sonic effects. Under the hood, the plugin uses two individual delay line paths. Each path’s behavior is determined by the character parameter: Thick and BBD provide warm, classic BBD-style tones, while Clean delivers a more transparent tone with greater modulation. This chorus has become a favorite in the iOS music community, combining vintage inspiration with modern control to deliver professional-quality sound in any production. This is an AUv3 Effect and requires a compatible host to work The in-app purchases are for tipping only, the app is fully functional without them The documentation is available at fredantoncorvest.com/FAC_Chorus.html
StringLab
This app is a digital synthesizer that uses physical string modeling to recreate the sounds of various instruments, particularly plucked or hammered strings. It allows users to explore acoustic physics and create unique instrument textures through extensive parameter experimentation.
- Karplus-Strong physical modeling
- Exciter Impact and Noise modes
- Resonator objects with feedback
- Frequency Dispersion support
- External live input
- Preset randomizer and manager
- Drag & Drop preset export
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StringLab is a physical string modeling synthesizer based on Karplus-Strong theory. It is capable of reproducing the sounds of many different types of instruments, but is especially useful in the reproduction of hammered or plucked strings and other types of percussive instruments. It works by passing carefully crafted waveforms and short bursts of white noise through a series of tuned delay lines. The delay lines have an internal feedback loop with a series of filters to mimic the natural decay of harmonics found in a real instrument. StringLab allows you to discover the character of real-world accoustics, exploring the physics of how materials interact. Many new and original textures are born out of experimenting with the settings, so don't be afraid to experiment and create your own unique and dynamic instruments. Features •Karplus Strong based physical modeling. •Exciter Impact with multiple modes. •Exciter Noise with many envelope driven filters. •2 resonator objects with feedback. •8 bands per object with inversion. •4 Coupling modes. •Supports Frequency Dispersion. •Feedback low/high Damping. •Per object Body Filter. •Pitch Deformity. •External live input mode. •Preset randomiser. •Build it Preset Manager & Favourites. •Search Presets. •Drag & Drop preset export of presets. •Supports Color Sets.
Screenshots
Verdict
The clearest difference is review sentiment: FAC Chorus at 95% against StringLab's 57%. FAC Chorus also leads on price ($6.99 vs $14.99) and rating (4.8 vs 4.3). StringLab's advantage is in-app purchases (none vs 3) and update cadence (every 10 days vs every 5 months). On ads 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
FAC Chorus costs $6.99 and StringLab $14.99 up front. FAC Chorus sells 3 one-off in-app purchases. StringLab asks for nothing beyond the download.
FAC Chorus holds the better App Store score, 4.8 against 4.3. Both are backed by a comparable volume of ratings — 61 and 14 respectively. Written reviews point the same way: 95% of FAC Chorus's written reviews are positive against 57% of StringLab's.
FAC Chorus ships an update every 5 months, StringLab every 10 days. The most recent releases landed on September 22, 2026 and September 21, 2026 respectively.
| Parameter | FAC Chorus | StringLab |
|---|---|---|
| Price | $6.99 — better | $14.99 |
| Rating | 4.8 (61 ratings) — better | 4.3 (14 ratings) |
| Positive reviews | 95.0% of reviews — better | 57.1% of reviews |
| Number of ratings | 61 — better | 14 |
| Update frequency | Every 5 months | Every 10 days — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases — better | Paid |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Requires iOS | 16.4 | 13.0 — better |
| Further details — not scored | ||
| Size | 4 MB | 45 MB |
| Age rating | 4+ | 4+ |
| Developer | Frederic Corvest | 4Pockets.com |
Customer experience
FAC Chorus
StringLab
In-app purchases
FAC Chorus
- Small Tip$1.99
- Medium Tip$4.99
- Large Tip$14.99
StringLab
No in-app purchases








