ButterSynth vs Tera Pro
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ButterSynth
This powerful synthesizer app offers a hybrid approach, combining wavetable, FM, and sample-based synthesis. Create unique sounds with a vast sonic range, advanced modulation, and a built-in effects rack. It caters to both experienced sound designers and beginners with extensive presets.
- Hybrid 6-oscillator synthesis (wavetable, FM, sample)
- Built-in wavetable editor
- FM engine with 4 operators
- Sample and Granulator engines
- 32-slot modulation matrix
- Internal FX rack with 16 modules
- Extensive preset library
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ButterSynth is a hybrid 6-oscillator wavetable/FM/sample-based AUV3 and standalone synthesizer with a vast sonic range, from gentle pads to screaming leads and basslines. Mix any combination of wavetable, FM, sample and other synthesis engines for one truly massive sound. For the more advanced users, you'll love using ButterSynth's thoughtfully designed interface, incredibly powerful modulation matrix, fully-featured internal FX rack, factory waveform and sample libraries, and almost limitless scope for fun, experimentation and sound design. For less experienced synth programmers, ButterSynth includes a library of hundreds of ready-to-use presets, sparking your creativity to start making music right away. Headline features include - Mix and match any combination of 6 synthesis engines to either emulate your favourite synths of yester-year or build a synth ready for the future. - Dual-wavetable engines also feature 9 phase modes, wave folding, and deep unison controls modelled on vintage hardware synths. - Built-in wavetable editor gives you the ability to tweak, morph, and hand-draw your own custom wavetables, with each wavetable supporting up to 256 frames. - FM engine offers 4 operators with a selection of 12 modulation paths. Each operator can be loaded with any waveform from the factory or user library, and can also self-modulate via the feedback dial. - Sample and Granulator engines both let you load samples (either imported or from the factory library) and control precisely how they are chopped, triggered and layered. Both also feature the same powerful unison modes available in the WT engine. - Highly configurable 32-slot modulation matrix featuring precise mix/max ranges, self-modulation (via the amount target), plus configurable response curves and layer modes. Simply long-tap any parameter to set it as a Mod destination! - Full suite of versatile control sources which includes: 4x MSEG-style looping curve envelopes, 4x LFOs, 4x step sequencers, X/Y pad with motion recording, 8x Macro dials and a powerful arpeggiator inspired by Kirnu Interactive’s Cream. - The EFX rack lets you build your own insert effects chain using any combination of the 16 built-in FX modules. Modules available at launch include delay, reverb, distortion, chorus, OTT compression etc. Note - FX parameters can also be targeted by the mod matrix, unlocking the possibility to program ‘per voice’ modulated effects. - All presets, wavetables, samples and other settings are stored in the Files app, making bulk import/export, backup and community sharing quick and easy. - All of this is housed in an irresistibly designed 4-tab UI that makes synth programming quick and fun.
Tera Pro
Explore a vast array of sound synthesis methods, from analog emulations to modern digital techniques. Combine modules for unique sonic textures, enhanced by an intelligent interface and realtime visual feedback. Expand your sound palette with additional modules available through in-app purchases.
- Multiple synthesis methods (analog, FM, spectral, additive)
- Physical modeling and wave shaping
- Intelligent user interface with realtime scopes
- Flexible module routing
- 128-voice polyphony with vintage voice modeling
- Seamless sound switching
- Extensive preset library
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Tera Pro brings together all major sound synthesis methods on one table. No matter if you want to recreate sounds from analogue legends or explore modern digital sounds with FM, Waveshaping or Wavetable synthesis. More can be added by In-App Purchases of new modules. Add some flavour of physical modelling and modules for additive synthesis. Combine them altogether for new sound experiences far beyond your wildest dreams. Tame this overwhelming amount of possibilities with Tera Pros intelligent user interface showing you only exactly what you need, paired with realtime oscilloscopes and level indicators helping you seeing what’s going on. Connect the modules with a flexible routing method without the visual cluttering of real wire cables needed in conventional modular synthesisers FAQ What does Tera Pro have that Tera Synth doesn't have ? 1) Additional Sound Modules - Spectrum oscillator ( borrowed from the heart of Addictive Synth ) - Wave shaper / folder opens the west coast synthesis - Vocal Morphing filter - KARPLUS (aka WaveGuide ) with new "Swarm" mode ( 3 detuned delays ) 2) Revised engine - Analog Polysynth Voice Modelling with characteristic subtle voice variations of timbre, pitch and temporal behaviour to get you "The" Analog Sound. - 128 vs 32 voices polyphony - Seamless Sound Switching: change presets during play without cutting off the sound. - 8 times unison for really heavy ambients - Envelope generators with Buchla style "end of cycle" trigger for generative music - Stack/Split Sounds - New effect section 3) Redesigned User Interface - Collapsible modules for clear view of modular structure - No more nasty popups for LFOs/Envelope generators - Realtime oscilloscopes added to selected modules 4) New Presets - About 1000 additional presets in there. Tera never sounded this good... Tera Pro Specifications - 128 voice Modular polyphonic Synthesiser - Mono/Dual/Split Voice Architecture - Modules for analog and FM synthesis - Modules for Spectral Synthesis and Additive Synthesis - Karplus Strong Physical Modelling and Wave Shaping - MIDI Polyphonic Expression (MPE) - Vintage voice modelling for organic warm sound character - 1800+ Factory presets included - PDF Manual included - Standalone, AUv3 and IAA compatible - Ableton Link - Bluetooth MIDI - ... Additional modules through In-App Purchases: - Classic Wavetable synthesis with Import - Classic 6-OP FM Synthesis fully compatible to DX7 sysex files. - BrainZ multiple synthesis module based on MI Plaits Eurorack module. - RingZ physical modelling module based on MI Rings Eurorack module. - CloudZ granular synthesis module based on MI Clouds Eurorack module.
Screenshots
Verdict
The clearest difference is price: Tera Pro at $6.99 against ButterSynth's $19.99. Tera Pro also leads on rating (4.6 vs 4.0) and update cadence (every 5 days vs every 2 months). ButterSynth's advantage is in-app purchases (none vs 6) and chart position (#190 vs unranked). On ratings volume, 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
ButterSynth costs $19.99 and Tera Pro $6.99 up front. Tera Pro sells 6 one-off in-app purchases. ButterSynth asks for nothing beyond the download.
Tera Pro holds the better App Store score, 4.6 against 4.0. Both are backed by a comparable volume of ratings — 62 and 155 respectively. Written reviews point the same way: 60% of ButterSynth's written reviews are positive against 69% of Tera Pro's.
ButterSynth ships an update every 2 months, Tera Pro every 5 days. The most recent releases landed on September 16, 2026 and September 20, 2026 respectively.
| Parameter | ButterSynth | Tera Pro |
|---|---|---|
| Price | $19.99 | $6.99 — better |
| Rating | 4.0 (62 ratings) | 4.6 (155 ratings) — better |
| Positive reviews | 59.6% of reviews | 69.4% of reviews — better |
| Number of ratings | 62 | 155 — better |
| Update frequency | Every 2 months | Every 5 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Free with in-app purchases — better |
| Best chart rank | #190 — better | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 14.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 468 MB | 306 MB |
| Age rating | 4+ | 4+ |
| Developer | Arto Vaarala | Harry Gohs |
Customer experience
ButterSynth
Tera Pro
User reviews
ButterSynth
From 62 App Store ratingsWhat we love
- ✨ Deep sound design capabilities
- 🎛️ Versatile modulation matrix
- 🔊 Great sound quality
- 💡 Innovative wavetable generator
- 🌟 Serum-like experience
Room to improve
- 📱 Fiddly on small screens
- 🐛 Crashes frequently
- 🐛 Disappears in Cubasis
- 🐛 Spikes CPU usage
- 🐛 Crashes on patch change
Tera Pro
From 155 App Store ratingsWhat we love
- 🎵 Exceptional sound quality and versatile synthesis capabilities
- 💡 Innovative modular workflow with flexible architecture
- 🎛️ Extensive preset library (1000+ presets)
- 🔧 Powerful sound design tools with multiple synthesis types
- 📱 Available on both iOS and macOS (M1)
Room to improve
- 🎮 Steep learning curve and complex UI
- ⌨️ Unconventional on-screen keyboard design
- 🐛 Frequent crashes and stability issues
- 🔊 Dangerously loud output without limiter
- ⚙️ UI elements sometimes unresponsive or laggy
Bugs and requests
ButterSynth
Reported bugs
39 issues- 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
Show 34 moreShow fewer
- 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
Requested features
20 requests- 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
Show 15 moreShow fewer
- 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
Tera Pro
Reported bugs
17 issues- App crashes on macOS and iOS
- Piano keyboard not appearing
- Wavetable module IAP producing no sound
- In-app purchases disappearing or not activating
- Presets causing white noise or feedback blasts
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- UI glitches preventing parameter adjustment
- Randomize function not working with wavetable oscillators
- Arpeggiator losing sync in AUM
- No sound output until patch toggling
- LFO panel crashes when adjusting settings
- Wavetable oscillator remaining silent
- MIDI Learn settings not clearable
- App not appearing in iPad Settings or Files app
- Patches with feedback that require MIDI Panic
- Inconsistent oscillator routing display
- Parameter adjustment randomly not working
- Sample rate unable to be changed
Requested features
15 requests- Undo/Redo functionality
- MIDI Panic button (prominent placement)
- Output limiter for safety
- Standard black and white keyboard option
- Favorites/bookmarking system for presets
Show 10 moreShow fewer
- MIDI Learn reset/clear functionality
- Key Hold button on main screen
- Sampler module
- Many-to-many modulation matrix
- Fully dark theme on all UI screens
- MIDI Program Change support
- Solo and Mute buttons for oscillators
- Partial number indicators for spectral oscillator
- Better file system integration for backups
- Improved velocity/aftertouch separation on keyboard
In-app purchases
ButterSynth
No in-app purchases
Tera Pro
- Library WaveShaper$0.99
- Module Waves$5.99
- FM 7 module$5.99
Show 3 moreShow fewer
- Module RingZ$5.99
- Module BrainZ$6.99
- Module CloudZ$9.99






