Comparison

WretchUp vs Robot Butter

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

WretchUp

This app offers a unique audio manipulation experience, allowing users to create sonic mayhem with pitch-shifted delays, filters, and sampling. It's designed for live performance and studio use, enabling musicians and sound enthusiasts to generate wild noises and unique effects.

Highlights
  • Pitch-shifted delay with feedback and filter
  • Live performance-oriented controls
  • Gesture-based play
  • Record vocals and instruments
  • Sample and manipulate loops
  • Inter-App-Audio and Audiobus support
Features
Read full description

An effect instrument anyone can play - sonic anarchy in the palm of your hand. iOS Mars: "Barely controlled chaos“, "sonic extremes“, "well suited for live use“ Music App Blog: "if you like the occasional dose of sonic mayhem, then this is an app that will let you make it" WretchUp is the sonic instrument from the imagination of Mouse on Mars Instruments. Used by the duo in their live performances, it's a playable effect inspired by analog hardware. Sing into it, speak into it, plug in an instrument, sample sounds, and then make sonic mayhem. It's been tested in Mouse on Mars' live shows and used in studio albums. But now it's available to anyone - whether you're a musician wanting to create unique sounds or you just want to make some wild noises and frighten friends and enemies. // FEATURES - Pitch-shifted delay with feedback and filter - Unique controls, designed to be used in live performance and tested onstage - Play with gestures, even without looking closely at the screen - Record vocals or instruments from the built-in mic or another input - Sample loops and change their speed - Adjust the feedback loop, pitch, and filter for unique sounds - Make inputs by holding down your finger, or lock input for continuous sampling - Inter-App-Audio supported - Audiobus supported www.mouseonmars.com/mominstruments Features artwork by Rupert Smyth. Pure Data-based, open source patch created by Florian Grote and Peter Kirn with Mouse on Mars. App design by Oliver Greschke. Powered by free and open source software libpd. Note: like all mic-based effects, you need to enable microphone input. If you accidentally did not allow mic input, you can allow later via: Device settings, WretchUp, Data settings, Microphone, allow mic input.

About

Robot Butter

This audio effect app creates dynamic soundscapes by blending animated modulation, adaptive reverb, and digital textures. It offers a fast, playable interface with direct control over key parameters and tempo-synced movement for evolving sound design.

Highlights
  • AUv3 audio effect for iPhone, iPad, and macOS
  • Animated modulation engine
  • Adaptive reverb stage
  • Tempo-synced LFO matrix
  • Digital texture effects
  • Built-in user manual
  • Factory and user presets
Read full description

Robot Butter is a creative AUv3 audio effect for compatible hosts on iOS & iPadOS. It blends animated modulation, adaptive reverb, tempo-aware movement, and digital texture into one fast, playable interface. At the core is the Robot engine, where Actuator, Viscosity, and Controller create the main motion and character of the signal. That signal then feeds Butter, an adaptive reverb stage designed to intelligently stay musical while responding to the effective movement of the Robot section. The result can move from focused width and pulse to washed ambience, strange motion, and unstable experimental color. The Chipset section extends the sound with a built-in assignable LFO matrix and a post-reverb System Bus reduction stage. Run the LFO freely in Hz or lock it to musical divisions for host-synced movement, then route it to key Robot or Butter controls for evolving motion. Add System Bus for subtle grain or push it harder for sharper, crushed digital edge. Robot Butter is designed to stay immediate. The interface gives you direct control over modulation, blend, depth, reverb shape, output mix, and motion timing without pushing you into a complicated modulation environment. A built-in user manual inside the standalone app includes overview pages, parameter explanations, quick-start guidance, glossary entries, MIDI notes, and troubleshooting help, with scrollable section pills that keep longer labels readable. Factory presets and user presets make it easy to jump from polished mix enhancement to stylized movement and aggressive sound design. Features: - Robot modulation engine with Actuator, Viscosity, Controller, and gain staging - Butter adaptive reverb with Churn, Emulsion, and Culture controls - Built-in LFO matrix with free or tempo-synced timing - Assignable LFO destinations across Robot and Butter parameters - System Bus sample-rate reduction stage for animated digital texture - Imaging modes including Mono, Wide, Ping, and Drift when stereo processing is available - Factory presets covering vocals, guitars, bass, keys, synths, drums, utility, and experimental categories - User preset save, recall, and delete support - Comprehensive built-in in-app user manual with quick-start, glossary, and troubleshooting sections - MIDI Learn, Host Learn support, and default CC mappings for hands-on control - Optional MIDI CC broadcast for compatible host-routing workflows - Host tempo sync with straight, dotted, and triplet divisions Use Robot Butter for vocal movement, guitar widening, synth pulse, drum bus animation, ambient wash design, or aggressive lo-fi modulation chains. It is built to move quickly from musical enhancement to animated destruction while keeping the workflow focused and playable.

Screenshots

WretchUp3 screens
Robot Butter4 screens

Verdict

The call

The clearest difference is price: WretchUp at $4.99 against Robot Butter's $14.99. WretchUp also leads on ratings volume (9 vs 2) and iOS requirement (11.0 vs 17.0). Robot Butter's advantage is rating (5.0 vs 3.1) and review sentiment (100% vs 91%). On update cadence, 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

WretchUp costs $4.99 and Robot Butter $14.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Robot Butter holds the better App Store score, 5.0 against 3.1. Both are backed by a comparable volume of ratings — 9 and 2 respectively. Written reviews point the same way: 91% of WretchUp's written reviews are positive against 100% of Robot Butter's.

UpkeepUpdate frequency

WretchUp ships an update every 3 weeks, Robot Butter monthly. The most recent releases landed on October 3, 2026 and October 17, 2026 respectively.

Scorecard5 real differences · 5 level
WretchUp versus Robot Butter: the parameters behind the verdict, then further details
ParameterWretchUpRobot Butter
Price$4.99 — better$14.99
Rating3.1 (9 ratings)5.0 (2 ratings) — better
Positive reviews90.9% of reviews100.0% of reviews — better
Number of ratings9 — better2
Update frequencyEvery 3 weeks — betterMonthly
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPodiPhone, iPad, Mac, Vision Pro — better
Requires iOS11.0 — better17.0
Further details — not scored
Size15 MB7 MB
Age rating4+4+
DeveloperMoMinstruments GbRChristian Thompson

Customer experience

WretchUp

All ratings9 ratings
Positive55.6%
Neutral0.0%
Negative44.4%
Written reviews11 reviews
Positive90.9%
Neutral0.0%
Negative9.1%

Robot Butter

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

WretchUp

No in-app purchases

None

Robot Butter

No in-app purchases

Questions

Is WretchUp free?
WretchUp costs $4.99, with no in-app purchases.
Is Robot Butter free?
Robot Butter costs $14.99, with no in-app purchases.
Which has better reviews, WretchUp or Robot Butter?
Robot Butter is rated higher. WretchUp averages 3.1 out of 5 from 9 ratings, while Robot Butter averages 5.0 from 2 ratings.
Do WretchUp or Robot Butter have ads?
Neither WretchUp nor Robot Butter shows ads.
Which is updated more often, WretchUp or Robot Butter?
WretchUp ships an update every 3 weeks, and Robot Butter monthly. Most recently, WretchUp was updated on October 3, 2026 and Robot Butter on October 17, 2026.

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