# ButterSynth — user reviews > 57 indexed App Store user reviews of ButterSynth by Arto Vaarala, rated 4.00/5 from 62 ratings. - Source: https://appshunter.io/ios/app/buttersynth/id1497419006/reviews - App overview in markdown: https://appshunter.io/ios/app/buttersynth/id1497419006.md - Rating breakdown: 5★ 39 · 4★ 6 · 3★ 5 · 2★ 4 · 1★ 8 ## What do users think of ButterSynth? Overall sentiment: mixed **Pros** - ✨ Deep sound design capabilities - 🎛️ Versatile modulation matrix - 🔊 Great sound quality - 💡 Innovative wavetable generator - 🌟 Serum-like experience - 📱 Available on phones/iPads - 🎹 Excellent for sound design - 🚀 Powerful and capable synth - 💯 Top-tier instrument - 🎶 Amazing workflow and sound - 💻 Desktop-class plugin on iOS - 🎨 Beautiful and intuitive UI - 🎚️ Wide range of filters - 🎛️ Loads of modulation capabilities - 💡 Unique random LFO feature - 🎚️ Good array of effects - 🎛️ Multiple oscillator types - 🎚️ FM synthesis included - 🎛️ Real 4-op FM synthesis - 🎨 Straightforward interface presentation - 🎚️ Great filters - 🎶 Excellent sound - 💡 Top-notch sound banks/patches - 🎛️ Highly customizable - 🎚️ Great for DnB - 🎛️ Can sound pretty or nasty - 🎚️ Granular controls - 🎛️ Deep and great sounding - 💡 Can recreate popular synths - 🎚️ Powerful and versatile - 🎛️ Good selection of presets - 🎚️ Excellent standalone app - 🎛️ Amazing wavetable synth - 🎚️ Good for soundscapes - 🎛️ Highly recommended **Cons** - 📱 Fiddly on small screens - 🐛 Crashes frequently - 🐛 Disappears in Cubasis - 🐛 Spikes CPU usage - 🐛 Crashes on patch change - 🐛 No audio on render/freeze - 🐛 Keyboard doesn't load on iPhone - 🐛 Audio Unit Extension quit error - 🐛 Unusable in GarageBand - 🐛 Preset changes on play - 🐛 Random crashes in Logic Pro - 🐛 Patches hang - 🐛 Limited wavetable selection - 🐛 Sample module buzz - 🐛 Simple LFOs - 🐛 Square wave LFO not square - 🐛 Step sequencer has glide - 🐛 Can't save custom presets - 🐛 No undo in wavetable editor - 🐛 AUv3 loading issues - 🐛 Unstable as AUv3 - 🐛 Patches sound different in AUv3 - 🐛 Crashes on iPhone with sequencer - 🐛 No keyboard in iPhone standalone - 🐛 Audio degradation in GarageBand - 🐛 Preset browser closes on selection - 🐛 Envelope curve is odd - 🐛 Release envelope ends abruptly - 🐛 Matrix fiddly with min/max knobs - 🐛 Missing filter key follow button - 🐛 Missing sustain pedal support - 🐛 Missing tunings - 🐛 Missing master detune - 🐛 Missing parameter lock - 🐛 Black borders on screen - 🐛 Automation not working - 🐛 No contact option for developer **Commonly reported bugs** - App crashing with AUM - Disappears in Cubasis randomly - Crashes all the time inside Logic - Changing a patch spikes CPU to 99% - Crashes on every patch change - No audio when rendering or freezing track - Keyboard doesn't load on iPhone - iOS18 broke ButterSynth (audio recording issues) - Failed to load as Auv3 - Crashes as soon as a preset is selected - Some patches hanging/sounding without input - CPU spikes to 100% on preset switching - Audio crackles on preset switching - Sample module has consistent buzz - LFOs are extremely simple (no phase offset) - Square wave LFO is not square (has slew) - Step sequencer always has glide/slew - Cannot save custom presets - No undo function in wave table editor - AUv3 plugin resets when ButterSynth crashes - Does not show up as auv3 in Cubasis, AUM, or Audio Evolution - Crashes regularly even on newest iPad - Preset changes every time play is pressed - Not resizing appropriately on smaller screens - Crashes with unison function in AUM - White noise on crash with unison - Sound continues after song stops in GarageBand - Preset changes on stop, rewind, or play in GarageBand - Keeps crashing in GarageBand (AUv3) - Patches in standalone sound different as AUv3 - Crashes when hitting play with arpeggiator/sequencer on iPhone - No keyboard appears in iPhone standalone mode - Audio Unit Extension quit error on export - Lots of crashes in standalone and hosted in AUM - MIDI not working - Automation still doesn’t work in Logic Pro - Random LFO is great for recording sequences - Preset browser closes each time a new preset is selected - Works as AUv3 after starting in standalone mode **Most requested features** - MPE popup possible on top of the auv3 - Button to hide built-in keyboard - Buffer size option - Additional MIDI mappings (e.g., arpeggiator toggle) - Sustain pedal support - Longer LFO speed for evolving soundscapes - Alternative skins/color themes - Pinable preset browser - Virtual keyboard to remain active while browser is pinned - Make app take up whole screen (no black borders) - Master detune - Parameter lock - More presets - Fix square wave LFO to be truly square - Fix step sequencer glide/slew for discrete steps - Undo function in wave table editor - Filter key follow button - Adjust envelope curves (especially release) - Easier way to adjust modulation matrix amount - Phase distortion inclusion ## Newest reviews (10 of 57) ### 4/5 — Amazing, but disappears in Cubasis randomly *2025-12-07* Amazing Synth. Great for DnB. Unfortunately one major issue for Cubasis users is that it randomly disappears from time to time leaving entire parts of your track missing. This makes it impossible to work with. ### 3/5 — Abandoned? *2025-08-03* This used to be my go-to synth for sound design but without even a bugfix release in over a year I’ve sadly come to the conclusion that it’s abandoned. It crashes all the time inside Logic, and desperately needs a button to hide the built in keyboard. ### 2/5 — Changing a patch spikes my m4 to 99 percent *2025-05-03, version 1.04* Changing a patch spikes my m4 to 99 percent. No way to contact the developer on their website. ### 4/5 — Everytime i render the track or freeze it Theres no audio *2025-03-06* this synth is good but it keeps crashing and bugging out and when I try to freeze or render it to audio it either crash or doesn’t show the audio or it will have like a little bit of the sound and the rest is gone in a bad way. Please fix this bc I use the sample for 808 and it’s good for sound design. Please fix this ### 3/5 — Great sounds, but some patches hanging *2024-10-16* I love the sounds. I hadn’t used this instrument in a while, started playing with it tonight and as I scroll through the presets, I’m finding that some are already sounding without me touching any keys. If I scroll past that patch, the next presets are also sounding, have to shut off all MIDI notes to get it to stop. ### 5/5 — Almost top tier, yet deserves 5/5 *2024-05-03* I’ve successfully recreated synths from popular songs with this app alone for a much lesser price. It would help a lot to make additional midi mappings such as a toggle for the arpeggiator. I’m fairly new to this app so this feature may or may not exist… yet. ### 4/5 — Great with hopeful potential *2024-04-13* I love the character of sound this app provides but I have a few requests for possible updates. 1) The square wave LFO is not square. It sounds like it’s running through a slew limiter. You can’t use it to tune interval jumps without glide. It always has glide. No trills possible. 2) Same for the step sequencer. It always has glide/slew. No discrete steps without glide. The modulation matrix is what sold me on the app but these basic routings offering unexpected results makes me wonder what else I might run into. The waveform system is absolutely wonderful and the filters sound great. Hopefully slew (and sustain pedal) can be addressed in updates. ### 3/5 — Great synth but can’t save custom preset?? *2024-02-28* Amazing synth, fun to use, but I can’t save my preset. Save button just doesn’t do anything… gonna have to use SynthMaster, I guess. Also, there’s no undo function in the wave table editor, which is very unfortunate. ### 5/5 — Excellent and hypertext pdf manual makes it a cut above. *2024-02-19* ButterSynth is not the absolutely most tweakable out there in iOS/iPadOS, nor the least. In practice it’s a top-tier instrument though. At the bottom end of customisable I suppose there are soundfont players with a dab of FX or the ability to layer (there are great ones for ipad and iphone), up top there are synths ported from ‘big boy’ DAWs maybe. It’s really good, coming with top-notch sound banks/patches, huge numbers of them. I downloaded one set from a third-party vendor (Jakob), and with his instructions it was integrated into Buttersynth in minutes. I feel I have to mention my findings from considerable testing with an iPad Pro 2 (before getting my iPad Pro M1 used, with ‘everything on’): short version, do not try to make any involved music on iOS devices unless you have at least 55Gb free SSD space. I began making sure 70Gb was my free SSD space in the end. I found 55Gb is the absolute minimum before several major issues occur like, ‘forgetting’ of the Audio Unit’s sound patch setting after you close the DAW and re-open it, spurious numerous faults, and the big one in GarageBand: GARAGEBAND WILL AUTOMATICALLY DEGRADE SOUND QUALITY IF YOUR DEVICE’S RESOURCES ARE STRETCHED. This includes audio being reduced to as little as 11kHz (compared to what you might believe is set to 44.1kHz!), and I suspect that some feedback to developers to the effect that their Audio Unit version sound patches are not the same as the standalone, could be exactly this deliberate deterioration by their DAW, or simply a by-product of low resources. If we compare this with PCs, their main OS literally is stated to need 200Gb completely free unused space on HDD or SSD to work with, so there ought not to be a surprise, we just haven’t outright been told - well, as an ex-IT man I am doing that now, to try and help other music creators the best way I can. Once you drop below 55Gb free SSD, fix that first, get it up to 70Gb free space to ensure AUv3 plugins can do their job, and the DAW give its best too. Apple had a USP using only SSD, but for taxing audio work, it’s a necessity now in my humble view. To round that aspect off, if you have iCloud as I do, don’t think you can ‘move’ stuff over as if it were a ‘Drive D’ or something, you cannot. Bad things happen. Either upgrade your device and/or get a backup drive for this. It’s not the Audio Unit Developer’s fault that there are technical constraints on user devices. This information was hard-fought for, so please save yourself a lot of trouble and do what’s needed or accept there are noticeable limitations (ie audible in your finalised song!). The dev is said to be a software engineer as a trade, but maybe in other realms, and I don’t know if that’s unusual or not, but the synth has been getting steadily improved, and looks to me as if the programming behind the scenes is pretty solid? I infer this because apart from the polished looks of it, the faults reported, seem to get fixed. Buttersynth is highly recommended, and as many have done, I already have a wide selection of synths in the iOS/iPadOS world, so this is a reasonably informed opinion. If you obtain and use it, I doubt you will regret the purchase, and the sound patches have actually incorporated multiple tweaks in a single movement of the mod wheel, which is vitally important if like me you use a ‘simple’ DAW like GarageBand, and want to make the sound go,a bit wild at points. GB for example, won’t record clever MIDI parameter alterations, or at least I haven’t managed to get twirls of other synths’ filter knobs etc, come through in the recorded track within AUv3 mode use. I make no bolder claims than these, it’s excellent. ### 4/5 — very unstable, but otherwise is great *2024-02-10, version 1.04* hey there. would like to tap in and give my feedback for buttersynth. ive been using buttersynth for 4 months now (since october 2023, its currently febuary 2024 as of writing this) and its been an okay experience. ive been using buttersynth as a AUV3 plugin in logic pro for ipad and ive had countless experiences of crashes at random or in certain senarios. im someone who jams out to make there music. ill record some ideas one by one, then chop up parts i like in order to use it in whatever song im making. during some of these jam sessions, buttersynth will crash on me at random and cause other buttersynth AUV3 plugins loaded and misc plugins on other tracks to completely reset to a state as if they where just loaded for the first time. despite all this, the plugin gives me a lot of control over how i want to make a synth pad, keyboard patch, or anything inbetween like a typical clap sound. ive used this plugin for things like bass lines and have had great results come out of it. so, if you are someone reading this who wants to buy this, id go for it, but be weary about its current stability. ## Most critical reviews (10 lowest-rated) ### 1/5 — App crashing *2026-06-03, version 1.04* With regular use, I’ve had it crash with AUM. Great app. When it’s not crashing. ### 1/5 — Crash Machine *2025-04-25, version 1.04* I have made many great sounds with this app across multiple songs, and in every song this app crashes. Totally unstable and disappointing. ### 1/5 — Crashes on every patch change *2025-03-30* It loads but on changing a patch it just disappears ### 1/5 — Everytime i render the track or freeze it Theres no audio *2025-03-12* this synth is good but it keeps crashing and bugging out and when I try to freeze or render it to audio it either crash or doesn’t show the audio or it will have like a little bit of the sound and the rest is gone in a bad way. Please fix this bc I use the sample for 808 and it’s good for sound design. Please fix this Update: it keeps crashing and it’s Annoying theres not even a buffer size on the synth please fix this please. I like using this synth for samples ### 1/5 — unusable *2025-01-20, version 1.04* Keyboard doesn’t load on iPhone. ### 1/5 — iOS18 Broke ButterSynth *2025-01-15* ButterSynth is a very powerful monster of a synth, but unfortunately since iOS18 was released it no longer works when trying to record the audio in a mixdown or manual track record in Cubasis 3. Months of dedication spent on creating super presets - all for nothing! ### 1/5 — It just simply doesn’t work *2024-12-02* This app just crashes as soon as a preset is selected, both in standalone and au3. I don’t think in 15 years I’ve bought an app that is so unusable. Refund requested. ### 1/5 — Not very good *2024-05-31* Limited selection of wave tables. Most are just single samples. Sample module has consistent buzz with unison and all effects/modulators off, whereas same sample in Koala with no effects sounds rich and full. Not sure what your signal path is like but I can’t get a reasonable sound. FM module is very limited. LFOs are extremely simple to the point uselessness. Like, seriously, no phase offset? Just amplitude and rate? I mean how’d you lose one of the three complete waveform descriptors? Terrible. ### 1/5 — Does not show up as auv3 *2024-02-09, version 1.04* In Cubasis, AUM, or Audio Evolution. Does show up as IAA, and standalone, if this bug is not fixed I want a refund. If it is fixed quickly I will amend this review, but currently one star as it is useless to me. ### 1/5 — Sounds great but *2024-02-03, version 1.04* Even with the newest iPad this app crashes regularly. Would not count on it as a performer. Ok for at home recording if you don’t mind it crashing semi regularly. ## Most praised reviews (10 highest-rated) ### 5/5 — Updated review years later. *2026-06-14* Originally I said that the synth wasn’t great on small screens, but after years of playing around in the iOS music app scene, I’ve come back to this synth as an absolute classic. I’ve gone deep on what’s available here, with two wavetables, with a wavetables generator tool that you can use to tweak harmonics, FM modulation, a wide arrange of filters…. Honestly, amazing. This synth should get much more attention. Whilst it is fiddly to edit on a phone screen, at least it is available on phones and plays presents developed on larger screens (when needed) perfectly. It’s honestly a brilliant balance of functionality and usability and I understand why compromises had to be made to keep it as functional as it is smaller screens. Honestly one of the best, if not the best synths in the iOS/iPadOS toolkit. Really excellent work. ### 5/5 — Most complete Pro SoftSynth *2026-06-01, version 1.04* Awesome and Functional...mpe popup possible on top of the auv3 As an addition? ### 5/5 — Serum for iPad *2026-05-16, version 1.04* This is one rude synth and I’m lovin it bada ba ba baah no joke this is dutty just how I like em ### 5/5 — Deep Surprises *2025-01-27* ButterSynth allows you to program from several different ideas. It is a deep, great sounding synth that can be a sounding as you like or weird and exotic. This is why I am so fond of this synthesizer. When programming there are many approaches that can be same sounding, but typically offer timbres that are somewhat similar and yet very different sounding until you realize the base of the sound starts from similar areas in the synth well producing different concepts taken from the same beginning. Personally, I’m not a big fan of the interface. It’s set up in a way that wastes a lot of screen space. And don’t necessarily come from the same style, which can be a little bit disconcerting and for me at least takes a little bit more time for me to figure out where I wanna go next. However, where I wanna go often ends up someplace different and interesting so in that respect as a user you end up in different places, different representations, and places you didn’t expect to find interesting but are. For that reason, I love this synth and find myself using it way more than I expect. Because of this, it does have a learning curve. I do hope that they approach the graphical user interface because I think that underneath this particular UI there is something exceptional waiting to occur. But if it never changes, there’s so much you can do with ButterSynth and I find myself drawn to its sound no matter that sometimes I spend more time than I would like trying to navigate features. The unexpected sometimes yields results I would personally never think of and that’s great.. ### 5/5 — Beautiful as a standalone, terrible as Auv3 *2024-12-14* I love the app as standalone, but sadly when trying to connect to Logic Pro for iPad as an Auv3, it is very miss or hit. Yep in that order, mostly i get failed to load. I have gone through all settings on both ButterSynth and LogicPro. If this ever gets fixed. This app would be the best synth app out there. Other than that I can’t use it ### 5/5 — Can’t believe it is butter lol *2024-08-30, version 1.04* Amazing workflow and sound. 10 stars! ### 5/5 — Best Wavetable Synth *2024-08-26* Hello, fantastic synth if you are after a Serum like experience. Has been a lot more stable for me than I’ve seen others report, M2 iPad Pro. I guess great power does require heavier resources. I wish the developer well and hope the rumours of an update are true, even if it is to just optimise it for more users. The synth itself is perfect. ### 5/5 — Haven’t explored completely but…… *2024-08-14* This is an absolute definite hall of famer in the upcoming Renaissance, My sincere apologies for not being able to write down the details but it’s coming. Two options 1) buy it 2) ignore option 1 and buy it now ### 5/5 — Awesome *2024-07-28* Hats off to the developer! Extremely capable synth that can sound pretty or nasty or anything in between. Loads of modulation capabilities you’re certainly not left wanting, an absolute must for sound designers. It’s one of those ones that stays permanently on your device ,reason being…it’s effing good ### 5/5 — Awesome and sending a note to devs *2024-07-04* Hey guys, firstly your app is awesome and I recently started building a live set with it included but I’ve hit an issue where on switching presets the cpu spikes to 100% and the audio crackles. This has been report back in 2023 in the audiobus forums and I see the updates were quite frequent but currently no update for 6 months (maybe due to the new iPads/OS launching?). Anyway can you let me know if this bug is on your radar please? I’m on an iPad mini 6 but it’s been confirmed on other devices also. For all readers of this comment please check the release notes of the app and you’ll see these guys work hard at supporting their product. The app sounds amazing and is totally worth every penny. Thank you. 5 well earned stars. --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-30.*