moodunits vs StringLab
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
moodunits
This application provides a collection of instrument and effect Audio Units for use within compatible music production apps. It features a sample-based instrument with pre-loaded sounds and essential effects like delay, reverb, and EQ, designed for ease of use and CPU efficiency.
- Sample-based instrument (Waverley)
- 30 factory presets with tweakable parameters
- Essential audio effects (delay, reverb, EQ, filter, distortion)
- CPU-light design
- AUv3 compatible
- User guide and store access
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Please note: moodunits have been designed as a set of instrument and effect Audio Units. You need to load moodunits into any AUv3 compatible host application running on iPad or iPhone, such as GarageBand or AUM. The moodunits app is not a standalone instrument. More about moodunits... Waverley is the principal instrument in the moodunits collection. It’s sample-based, but it isn’t a fully-fledged sampling app that allows you to load and edit your own samples. There are already great apps out there that allow you to do that. Waverley in moodunits is pre-loaded with 30 factory sounds, that can be tweaked to taste via parameters that will hopefully be familiar to most of you. However, don’t worry if some parameter names look technical or scary - just experiment! You can’t really “break” Waverley or make “bad” sounds with it. moodunits also comes with some basic effects, allowing you to create a great sounding musical project using just moodunits and your favourite AU host. In keeping with the moodunits design principal, the effects are light on CPU and expose a few essential parameters. They're probably not going to replace your favourite bells and whistles mega reverb or delay, but their simplicity might come as a refreshing change. Currently these effects include a delay, reverb, low-pass filter, 10-band EQ, peak limiter and distortion. Please note: The moodunits app is not a standalone instrument, but can be used to access a detailed PDF user guide and the MU Store for additional downloads. Once you run the app, your moodunits are registered on your device and are ready to be used for music projects in your AU host of choice. For instructions on how to use Audio Units, please refer to relevant documentation for your host, e.g. GarageBand or AUM, etc. Note for advanced users: with the exception of the filter cutoff frequency and resonance in the filter AU, none of the parameters are exposed for automation. Also, please note that the design goals for moodunits is focussed on ease of use, so some advanced users may find the features basic. The screenshots and demo videos online should give you a good idea of what's possible. If in doubt, please ask.
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 price: moodunits at $3.99 against StringLab's $14.99. moodunits also leads on review sentiment (93% vs 63%) and rating (4.5 vs 4.3). StringLab's advantage is iOS requirement (13.0 vs 15.6). 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
moodunits costs $3.99 and StringLab $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.
moodunits holds the better App Store score, 4.5 against 4.3. Both are backed by a comparable volume of ratings — 50 and 15 respectively. Written reviews point the same way: 93% of moodunits's written reviews are positive against 63% of StringLab's.
moodunits ships an update every 5 days, StringLab every 10 days. The most recent releases landed on November 12, 2026 and November 4, 2026 respectively.
| Parameter | moodunits | StringLab |
|---|---|---|
| Price | $3.99 — better | $14.99 |
| Rating | 4.5 (50 ratings) — better | 4.3 (15 ratings) |
| Positive reviews | 92.5% of reviews — better | 62.5% of reviews |
| Number of ratings | 50 — better | 15 |
| Update frequency | Every 5 days — better | Every 10 days |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.6 | 13.0 — better |
| Further details — not scored | ||
| Size | 3.0 GB | 45 MB |
| Age rating | 4+ | 4+ |
| Developer | Rob Jackson | 4Pockets.com |
Customer experience
moodunits
StringLab
Bugs and requests
moodunits
Reported bugs
3 issues- Expansion packs not showing initially
- Crashes on exporting audio
- MU Store Error: Download could not be started
Requested features
7 requests- New packs, presets, synths
- More effects options (e.g., chorus)
- Reduced bundle for all moods
- Automation for iOS
- Own instrument sampler
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- More FX and Units
- Juno pads and basses
StringLab
Not enough reviews yet to summarise bugs or requests.
In-app purchases
moodunits
No in-app purchases
StringLab
No in-app purchases









