Comparison

KASPAR vs Agonizer

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

Head to head
About

KASPAR

This powerful synthesizer app offers 8 polyphonic engines with extensive morphing, layering, and modulation capabilities. Create complex sounds with 24 oscillators, 8 filters, and built-in stereo effects. It integrates seamlessly with DAWs and other music apps.

Highlights
  • 8 polyphonic synth engines
  • Multi-Engine Automorphing
  • Extensive modulation system
  • Poly aftertouch support
  • 2 stereo FX busses
  • Audio Unit plugin integration
  • Inter-App Audio and Audiobus support
Read full description

Harness the enormous power of 8 polyphonic synths: meet KASPAR Supersynthesizer! Featuring our cutting edge Multi-Engine Automorphing SuperSynthesis technology, KASPAR is a gigantic machine. A total of 24 oscillators, 8 filters, 8 arps; extensive morphing, automorphing, and layering abilities; a powerful modulation system; poly aftertouch; 2 FX Busses filled with fully stereo Yonac effects — just a few of the amazing features of this behemoth synth! KASPAR comes with tons of pro features. In addition to extensive MIDI capabilities, Inter-App Audio, and Audiobus, it also works as an Audio Unit plug in. Just fire it up in GarageBand or your favorite DAW for even more KASPAR goodness! Top Notch Sound Generation • 8 fully-featured polyphonic synth engines, each with, — 3 oscillators (24 systemwide total!) — Over 20 unique waveforms per oscillator — Special 6-stage ‘dADSHR’ envelopes — 14 types of filters to choose from — Dedicated filter envelope — Arpeggiator with multiple modes — Chordmaker - easily program & play chords by touching a single key — Powerful modulation features (see below) Extensive Modulation • Each synth has a dedicated mod assign matrix with 6 slots • 20 mod targets to choose from, including pitch, timbre, filters and more • Each target can be modulated by a continuous signal, as well as a control signal • 2 LFOs per synth • Modulation envelope • Poly aftertouch • Velocity, Mod Wheel & Key Tracking Morphing • 4 morph groups with onscreen control pad • Automorphing: simply draw a figure on the pad and KASPAR automatically tracks it • Modulate the morph using the x- and y-controls • 6 automorph trigger modes • 4 automorph looping modes • Adjustable, beat-syncable pathread & modulation speeds Layering • Combine the 8 KASPAR synth engines in infinite ways • Each synth comes with dedicated volume and panning, as well as FX1 & FX2 send controls • Conveniently map the synths to regions of the keyboard: great for ‘splitting’ or ‘layering’ multiple synth patches • Each engine has its own transpose & drift controls, as well as adjustable pitch bending, velocity, and aftertouch ranges Professional FX • Two independent FX busses • Each bus contains 8 state-of-the-art stereo FX specially designed for KASPAR • Simply drag-and-drop to change FX signal flow • FX include: — Analog-modeling compressor — 6 band parametric EQ with 9 filter options per band — Stereo chorus with 10 parameters — Stereo phaser — Stereo flanger — Amplifier with 4 virtual circuit types and 4 cabinet types — Stereo delay with BPM syncing — Algorithmic reverb with 14 parameters Professional Features • Standalone app features Inter-App Audio, Audiobus, and Ableton Link • Comes packaged with FREE Audio Unit plugin, with native processing at any standard sample rate • Crystal clear, super high quality audio generation • Virtual ribbon control with polyphonic aftertouch, as well as classic keyboard • Virtual KB velocity with adjustable sensitivity • Extensive MIDI Learn options • MIDI Maps manager with MIDI CC profile saving • Over 300 high quality presets, including an exclusive bank by New Wave Presets • Powerful preset management system: save, share & edit presets System Requirements • Recommended for iPad Air, iPad Pro, iPad Mini 2, or newer

About

Agonizer

This app is a monophonic synthesizer focused on bass sounds, developed with a synth bass expert. It features dual wavetable oscillators, a mangle section, and built-in stereo effects. It supports MPE controllers and various audio/MIDI connectivity options for standalone or app-to-app use.

Highlights
  • Monophonic synth engine for bass
  • Dual wavetable oscillators
  • Built-in stereo effects
  • MPE controller support
  • Standalone and AUv3 operation
  • 140+ factory presets
Features
Read full description

Agonizer is a monophonic synthesizer designed in collaboration with YouTuber and synth bass expert Jakob Haq of haQ attaQ Overview: * Monophonic Synth Engine with focus on Bass * Built-in stereo effects * 140+ fine tuned factory presets designed by Jakob Haq * Supports ROLI Seaboard and other MPE controllers out of the box * Standalone operation with support for USB audio interfaces, wired, network & bluetooth MIDI * Audio Unit v3 Extension * Inter App Audio support * Audiobus support * Ableton Link Synth Voice: * Dual Wavetable Oscillators with 40+ Wavetables, Morphing & X-Mod * Dedicated sub osc & noise source * Mangle Section with pre-filter Drive, Bitcrush, Lift and Push controls * VA Ladder filter * Wobulator (Highly tweak-able Sequenced LFO) * LFO with Key and BPM Sync * Variable Slope AD & ADSR Envelopes * Tube based master drive Effects: * 2x stereo effect units * Vintage Chorus * Digital Delay Presets: * Factory bank including 140+ presets designed by Jakob Haq * Preset Management with Templates & Categories * Shared User Presets between Standalone and AUv3 versions * Preset Export & Import Connectivity: * Standalone * AUv3 Instrument * Inter-App Audio Instrument * Audiobus Instrument Requirements: * iOS12+ * iPad Air 2 or newer

Screenshots

Agonizer4 screens

Verdict

The call

The clearest difference is in-app purchases: KASPAR at none against Agonizer's 3. Agonizer's advantage is update cadence (every 5 months vs every 16 months) and rating (4.8 vs 4.6). On price, review sentiment, ratings volume and ads 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

KASPAR costs $19.99 and Agonizer $19.99 up front. Agonizer sells 3 one-off in-app purchases. KASPAR asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Agonizer holds the better App Store score, 4.8 against 4.6. Both are backed by a comparable volume of ratings — 91 and 203 respectively. Written reviews point the same way: 75% of KASPAR's written reviews are positive against 78% of Agonizer's.

UpkeepUpdate frequency

KASPAR ships an update every 16 months, Agonizer every 5 months. The most recent releases landed on October 6, 2026 and October 14, 2026 respectively.

Scorecard5 real differences · 5 level
KASPAR versus Agonizer: the parameters behind the verdict, then further details
ParameterKASPARAgonizer
Price$19.99$19.99
Rating4.6 (91 ratings)4.8 (203 ratings) — better
Positive reviews75.0% of reviews77.8% of reviews — better
Number of ratings91203 — better
Update frequencyEvery 16 monthsEvery 5 months — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
DevicesiPadiPhone, iPad, iPod — better
Requires iOS11.011.0
Further details — not scored
Size64 MB362 MB
Age rating4+4+
DeveloperYonac Inc.Kai Aras

Customer experience

KASPAR

All ratings91 ratings
Positive87.9%
Neutral4.4%
Negative7.7%
Written reviews56 reviews
Positive75.0%
Neutral10.7%
Negative14.3%

Agonizer

All ratings203 ratings
Positive95.6%
Neutral1.5%
Negative3.0%
Written reviews81 reviews
Positive77.8%
Neutral6.2%
Negative16.0%

User reviews

KASPAR

From 91 App Store ratings

What we love

  • ✨ Incredible power and depth
  • 🔊 Amazing and unique sound quality
  • 👍 Easy to use and intuitive UI
  • 💡 Highly configurable and flexible
  • 🎛️ Advanced sound shaping possibilities

Room to improve

  • 🐛 Occasional crashes and instability
  • 💻 High CPU usage
  • 🐞 Bugs in AUv3 implementation
  • 🖼️ UI scaling issues in some DAWs
  • 🤔 Presets can be uninspired or limited

Agonizer

From 203 App Store ratings

What we love

  • 🎵 Excellent sound quality and unique bass tones
  • 🎨 Intuitive and well-designed user interface
  • ⚙️ Powerful modulation and sound design capabilities
  • 🎛️ Wobulator feature for creative bass manipulation
  • 📦 Great presets included with the app

Room to improve

  • 🐛 Keyboard legato/mono-synth behavior inconsistent
  • 🐛 Frequent crashes in host applications (AUM, Cubasis, Audiobus)
  • 🐛 No sound output in GarageBand and some AU hosts
  • 🐛 App freezes on splash screen with iOS 18.3
  • 🐛 UI responsiveness issues and knob lag

Bugs and requests

KASPAR

Reported bugs

12 issues
  • Sound muted in solo mode for some synths
  • Synth crashes when loading as AUv3 in Roland Zenbeats
  • FX chain not working
  • Program change messages not followed as AUv3 in Cubasis internal track
  • UI does not scale to full screen in Cubasis 3
Show 7 more
  • App crashes when clicking 'help' offline
  • Random crashes inside host (GarageBand/Cubasis) as AUv3
  • Multiple instances play simultaneously when track is not armed
  • Keeps crashing in BeatMaker 3 as AUv3
  • Does not fit screen correctly in Cubasis 3
  • Modulation matrix has issues with aftertouch modulating cutoff frequency
  • Copying presets between layers gets messed up with aftertouch modulation

Requested features

11 requests
  • Add a step sequencer
  • Improve preset variety and inspiration
  • Fix AUv3 program change issues
  • Address UI scaling problems in DAWs
  • Implement MIDI out functionality
Show 6 more
  • Expand modulation matrix capabilities
  • Fix aftertouch modulation issues
  • Integrate help within the app
  • Relocate performance buttons to Morph page
  • Add master volume control to Morph page
  • Add Bluetooth audio support

Agonizer

Reported bugs

16 issues
  • Keyboard does not properly handle legato/mono-synth note priority
  • Crashes in Audiobus, AUM, and Cubasis host applications
  • No sound output when used as AUv3 plugin in hosts
  • No sound in GarageBand integration
  • App freezes on splash screen with iOS 18.3
Show 11 more
  • Stuck notes and failed note triggering
  • Scream button malfunction when switching presets
  • Cutoff knob lag in AUv3 scenarios
  • UI jitter and text cutoff on iPhone
  • Favorite preset feature not working on iPhone
  • Program change not working properly in hosts
  • Always opens with init preset in host applications
  • Modulation matrix sensitivity too high (2% movement = large range)
  • Audio output peaks in red with no sound
  • Permanent clipping/damaged audio output
  • Misleading IAP pricing display (showing 'FREE' for paid content)

Requested features

10 requests
  • Polyphony mode or toggle between mono and poly
  • Envelope drawing capability instead of preset selection
  • Menu-based waveform selection instead of cycling
  • Arpeggiator function
  • Preset browser search and favorites filter
Show 5 more
  • Extended automation control for all knobs
  • Keytracking for filter
  • Reverb effect
  • Accelerometer/gyroscopic velocity sensitivity
  • Customizable number of keyboard keys

In-app purchases

None

KASPAR

No in-app purchases

3 purchases

Agonizer

One-time3
  • Chrome Oasis Pack$3.99
  • Circuit Bender Pack$3.99
  • Neon Nightmare Pack$4.99

Questions

Is KASPAR free?
KASPAR costs $19.99, with no in-app purchases.
Is Agonizer free?
Agonizer costs $19.99, and also offers in-app purchases.
Which has better reviews, KASPAR or Agonizer?
Agonizer is rated higher. KASPAR averages 4.6 out of 5 from 91 ratings, while Agonizer averages 4.8 from 203 ratings.
Do KASPAR or Agonizer have ads?
Neither KASPAR nor Agonizer shows ads.
Which is updated more often, KASPAR or Agonizer?
KASPAR ships an update every 16 months, and Agonizer every 5 months. Most recently, KASPAR was updated on October 6, 2026 and Agonizer on October 14, 2026.

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