StepBud vs Agonizer
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
StepBud
This app is a versatile MIDI sequencer that allows for unlimited steps and detailed control over each step's parameters. It integrates with other music apps and supports various sequencing modes for creative performances.
- Unlimited steps
- Step parameter control (note, velocity, rate, etc.)
- Custom MIDI CC messages
- Step locking and skipping
- Master fader with copy/shift modes
- Step Editor for detailed note editing
- Arpeggio modes (up, down, random)
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StepBud is a MIDI Sequencer with Audio Unit AUv3 plugin, Audiobus and Ableton Link. Add an unlimited number of steps to your sequencer. Your steps appear with a LED and a fader on top of your screen. You can change the active mode that your step faders displaying/controlling. - Set the current note or chord in range of the scale and key you selected with respect the range of the octave you want to focus, - Set the velocity, rate, gate time, modulation, pitch bend, portamento, probability and swing for each step, - Try increasing the rate and repeat count your steps if you want to add more flavor. - Send unlimited custom MIDI CC messages if you want to control your hardware or software synth parameters. - Lock steps if you don't want them to change their value. - Skip steps for creating interesting live performances. Below the step faders, you have a master fader where you can control your entire sequencer. It has two modes which you can change from the settings strip on the bottom of the app. - In copy mode, it assigns its value to each step. - In shift mode, it shifts up or down each step. If you want to go off-scale or try some crazy chords on some of your steps, or maybe on all of them, you can go to the Step Editor by double tapping the LED of the step you want to edit. In StepBud's powerful Step Editor, you can set your step's notes either from the virtual keyboard or your connected MIDI keyboard. Don't forget to enable MIDI in port of your MIDI keyboard or the you want to receive MIDI from the settings menu. You may also preview the selected notes by pressing the preview button in Step Editor for making sure you created the perfect sound for your particular step. You can also toggle the steps you want to disable by tapping its LED. If you long-press the LED, you can access a menu where you may copy/paste the steps around, remove them or edit them. If you enable the lock mode from the settings strip on the bottom of the app, you may adjust each visible step fader on the screen by a single swipe gesture without having to lift your finger up. Try to change your arppegio mode from the settings strip. You can sequence your steps up, down, up-down or random order. StepBud is a MIDI sequencer app and it does not generate sounds itself. You need to route its MIDI out port in the settings menu to the audio app you want to sequence. Please note that you need to have an iOS 11+ device and an Audio Unit host application such as AUM, apeMatrix, Cubasis, BeatMaker or Audiobus in order to use the StepBud as an Audio Unit plugin. And don't forget to route StepBud's MIDI out to the app or audio unit you want to sequence. StepBud's MIDI layer powered by free and open-source project AudioKit https://github.com/AudioKit/AudioKit Also, StepBud offers its core components for free on GitHub. Feel free to star, fork or contribute. https://github.com/cemolcay/MusicTheory https://github.com/cemolcay/LiveFader https://github.com/cemolcay/MIDIEventKit
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.
- Monophonic synth engine for bass
- Dual wavetable oscillators
- Built-in stereo effects
- MPE controller support
- Standalone and AUv3 operation
- 140+ factory presets
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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
Verdict
The clearest difference is in-app purchases: StepBud at none against Agonizer's 3. StepBud also leads on update cadence (fortnightly vs every 5 months) and price ($4.99 vs $7.99). Agonizer's advantage is rating (4.8 vs 4.4) and ratings volume (203 vs 38). On review sentiment, 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
StepBud costs $4.99 and Agonizer $7.99 up front. Agonizer sells 3 one-off in-app purchases. StepBud asks for nothing beyond the download.
Agonizer holds the better App Store score, 4.8 against 4.4. That said, the two scores are not equally well evidenced: Agonizer has 203 ratings behind it against 38, so its average is the more settled of the two. Written reviews point the same way: 71% of StepBud's written reviews are positive against 78% of Agonizer's.
StepBud ships an update fortnightly, Agonizer every 5 months. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.
| Parameter | StepBud | Agonizer |
|---|---|---|
| Price | $4.99 — better | $7.99 |
| Rating | 4.4 (38 ratings) | 4.8 (203 ratings) — better |
| Positive reviews | 70.6% of reviews | 78.0% of reviews — better |
| Number of ratings | 38 | 203 — better |
| Update frequency | Fortnightly — better | Every 5 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Best chart rank | #200 — better | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 13.0 | 11.0 — better |
| Further details — not scored | ||
| Size | 8 MB | 362 MB |
| Age rating | 4+ | 4+ |
| Developer | Cem Olcay | Kai Aras |
Customer experience
StepBud
Agonizer
Bugs and requests
StepBud
Not enough reviews yet to summarise bugs or requests.
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
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- 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
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- Extended automation control for all knobs
- Keytracking for filter
- Reverb effect
- Accelerometer/gyroscopic velocity sensitivity
- Customizable number of keyboard keys
In-app purchases
StepBud
No in-app purchases
Agonizer
- Neon Nightmare Pack$1.99
- Chrome Oasis Pack$1.99
- Circuit Bender Pack$1.99









